diff --git a/apps/webapp/app/components/runs/v3/ReplayRunDialog.tsx b/apps/webapp/app/components/runs/v3/ReplayRunDialog.tsx
index 9192020e1bc..e42a2122abe 100644
--- a/apps/webapp/app/components/runs/v3/ReplayRunDialog.tsx
+++ b/apps/webapp/app/components/runs/v3/ReplayRunDialog.tsx
@@ -201,6 +201,7 @@ function ReplayForm({
       tags,
       version,
       machine,
+      region,
       prioritySeconds,
     },
   ] = useForm({
@@ -357,6 +358,35 @@ function ReplayForm({
                 )}
                 <FormError id={version.errorId}>{version.error}</FormError>
               </InputGroup>
+              {replayData.regions.length > 1 && (
+                <InputGroup>
+                  <Label htmlFor={region.id} variant="small">
+                    Region
+                  </Label>
+                  <Select
+                    {...conform.select(region)}
+                    variant="tertiary/small"
+                    placeholder={replayData.disableVersionSelection ? "–" : undefined}
+                    dropdownIcon
+                    items={replayData.regions}
+                    defaultValue={replayData.region ?? undefined}
+                    disabled={replayData.disableVersionSelection}
+                  >
+                    {replayData.regions.map((r) => (
+                      <SelectItem key={r.name} value={r.name}>
+                        {r.description ? `${r.name} — ${r.description}` : r.name}
+                        {r.isDefault ? " (default)" : ""}
+                      </SelectItem>
+                    ))}
+                  </Select>
+                  {replayData.disableVersionSelection ? (
+                    <Hint>Region is not available in the development environment.</Hint>
+                  ) : (
+                    <Hint>Overrides the region for this run.</Hint>
+                  )}
+                  <FormError id={region.errorId}>{region.error}</FormError>
+                </InputGroup>
+              )}
               <InputGroup>
                 <Label htmlFor={queue.id} variant="small">
                   Queue
diff --git a/apps/webapp/app/routes/_app.orgs.$organizationSlug.projects.$projectParam.env.$envParam.test.tasks.$taskParam/route.tsx b/apps/webapp/app/routes/_app.orgs.$organizationSlug.projects.$projectParam.env.$envParam.test.tasks.$taskParam/route.tsx
index d452a757136..a87cc4530d2 100644
--- a/apps/webapp/app/routes/_app.orgs.$organizationSlug.projects.$projectParam.env.$envParam.test.tasks.$taskParam/route.tsx
+++ b/apps/webapp/app/routes/_app.orgs.$organizationSlug.projects.$projectParam.env.$envParam.test.tasks.$taskParam/route.tsx
@@ -54,7 +54,7 @@ import {
   TestTaskPresenter,
 } from "~/presenters/v3/TestTaskPresenter.server";
 import { logger } from "~/services/logger.server";
-import { requireUserId } from "~/services/session.server";
+import { requireUser } from "~/services/session.server";
 import { cn } from "~/utils/cn";
 import { docsPath, v3RunSpanPath, v3TaskParamsSchema, v3TestPath } from "~/utils/pathBuilder";
 import { TestTaskService } from "~/v3/services/testTask.server";
@@ -75,14 +75,15 @@ import { DialogClose, DialogDescription } from "@radix-ui/react-dialog";
 import { FormButtons } from "~/components/primitives/FormButtons";
 import { $replica } from "~/db.server";
 import { clickhouseClient } from "~/services/clickhouseInstance.server";
+import { RegionsPresenter, type Region } from "~/presenters/v3/RegionsPresenter.server";
 
 type FormAction = "create-template" | "delete-template" | "run-scheduled" | "run-standard";
 
 export const loader = async ({ request, params }: LoaderFunctionArgs) => {
-  const userId = await requireUserId(request);
+  const user = await requireUser(request);
   const { projectParam, organizationSlug, envParam, taskParam } = v3TaskParamsSchema.parse(params);
 
-  const project = await findProjectBySlug(organizationSlug, projectParam, userId);
+  const project = await findProjectBySlug(organizationSlug, projectParam, user.id);
   if (!project) {
     throw new Response(undefined, {
       status: 404,
@@ -90,7 +91,7 @@ export const loader = async ({ request, params }: LoaderFunctionArgs) => {
     });
   }
 
-  const environment = await findEnvironmentBySlug(project.id, envParam, userId);
+  const environment = await findEnvironmentBySlug(project.id, envParam, user.id);
   if (!environment) {
     throw new Response(undefined, {
       status: 404,
@@ -100,14 +101,21 @@ export const loader = async ({ request, params }: LoaderFunctionArgs) => {
 
   const presenter = new TestTaskPresenter($replica, clickhouseClient);
   try {
-    const result = await presenter.call({
-      userId,
-      projectId: project.id,
-      taskIdentifier: taskParam,
-      environment: environment,
-    });
-
-    return typedjson(result);
+    const [result, regionsResult] = await Promise.all([
+      presenter.call({
+        userId: user.id,
+        projectId: project.id,
+        taskIdentifier: taskParam,
+        environment: environment,
+      }),
+      new RegionsPresenter().call({
+        userId: user.id,
+        projectSlug: projectParam,
+        isAdmin: user.admin || user.isImpersonating,
+      }),
+    ]);
+
+    return typedjson({ ...result, regions: regionsResult.regions });
   } catch (error) {
     return redirectWithErrorMessage(
       v3TestPath({ slug: organizationSlug }, { slug: projectParam }, environment),
@@ -118,15 +126,15 @@ export const loader = async ({ request, params }: LoaderFunctionArgs) => {
 };
 
 export const action: ActionFunction = async ({ request, params }) => {
-  const userId = await requireUserId(request);
+  const user = await requireUser(request);
   const { organizationSlug, projectParam, envParam } = v3TaskParamsSchema.parse(params);
 
-  const project = await findProjectBySlug(organizationSlug, projectParam, userId);
+  const project = await findProjectBySlug(organizationSlug, projectParam, user.id);
   if (!project) {
     return redirectBackWithErrorMessage(request, "Project not found");
   }
 
-  const environment = await findEnvironmentBySlug(project.id, envParam, userId);
+  const environment = await findEnvironmentBySlug(project.id, envParam, user.id);
 
   if (!environment) {
     return redirectBackWithErrorMessage(request, "Environment not found");
@@ -290,6 +298,7 @@ export default function Page() {
           templates={result.taskRunTemplates}
           disableVersionSelection={result.disableVersionSelection}
           allowArbitraryQueues={result.allowArbitraryQueues}
+          regions={result.regions}
         />
       );
     }
@@ -304,6 +313,7 @@ export default function Page() {
           possibleTimezones={result.possibleTimezones}
           disableVersionSelection={result.disableVersionSelection}
           allowArbitraryQueues={result.allowArbitraryQueues}
+          regions={result.regions}
         />
       );
     }
@@ -324,6 +334,7 @@ function StandardTaskForm({
   templates,
   disableVersionSelection,
   allowArbitraryQueues,
+  regions,
 }: {
   task: StandardTaskResult["task"];
   queues: Required<StandardTaskResult>["queue"][];
@@ -332,6 +343,7 @@ function StandardTaskForm({
   templates: RunTemplate[];
   disableVersionSelection: boolean;
   allowArbitraryQueues: boolean;
+  regions: Region[];
 }) {
   const environment = useEnvironment();
   const { value, replace } = useSearchParams();
@@ -373,6 +385,12 @@ function StandardTaskForm({
   );
   const [queueValue, setQueueValue] = useState<string | undefined>(lastRun?.queue);
   const [machineValue, setMachineValue] = useState<string | undefined>(lastRun?.machinePreset);
+  const isDev = environment.type === "DEVELOPMENT";
+  const defaultRegion = regions.find((r) => r.isDefault);
+  const [regionValue, setRegionValue] = useState<string | undefined>(
+    isDev ? undefined : defaultRegion?.name
+  );
+
   const [maxAttemptsValue, setMaxAttemptsValue] = useState<number | undefined>(
     lastRun?.maxAttempts
   );
@@ -381,6 +399,12 @@ function StandardTaskForm({
   );
   const [tagsValue, setTagsValue] = useState<string[]>(lastRun?.runTags ?? []);
 
+  const regionItems = regions.map((r) => ({
+    value: r.name,
+    label: r.description ? `${r.name} — ${r.description}` : r.name,
+    isDefault: r.isDefault,
+  }));
+
   const queueItems = queues.map((q) => ({
     value: q.type === "task" ? `task/${q.name}` : q.name,
     label: q.name,
@@ -409,6 +433,7 @@ function StandardTaskForm({
       tags,
       version,
       machine,
+      region,
       prioritySeconds,
     },
   ] = useForm({
@@ -580,6 +605,45 @@ function StandardTaskForm({
                 )}
                 <FormError id={version.errorId}>{version.error}</FormError>
               </InputGroup>
+              {regionItems.length > 1 && (
+                <InputGroup>
+                  <Label htmlFor={region.id} variant="small">
+                    Region
+                  </Label>
+                  {/* Our Select primitive uses Ariakit under the hood, which treats
+                      value={undefined} as uncontrolled, keeping stale internal state when
+                      switching environments. The key forces a remount so it reinitializes
+                      with the correct defaultValue. */}
+                  <Select
+                    key={`region-${environment.id}`}
+                    {...conform.select(region)}
+                    variant="tertiary/small"
+                    placeholder={isDev ? "–" : undefined}
+                    dropdownIcon
+                    items={regionItems}
+                    defaultValue={isDev ? undefined : defaultRegion?.name}
+                    value={isDev ? undefined : regionValue}
+                    setValue={isDev ? undefined : (e) => {
+                      if (Array.isArray(e)) return;
+                      setRegionValue(e);
+                    }}
+                    disabled={isDev}
+                  >
+                    {regionItems.map((r) => (
+                      <SelectItem key={r.value} value={r.value}>
+                        {r.label}
+                        {r.isDefault ? " (default)" : ""}
+                      </SelectItem>
+                    ))}
+                  </Select>
+                  {isDev ? (
+                    <Hint>Region is not available in the development environment.</Hint>
+                  ) : (
+                    <Hint>Overrides the region for this run.</Hint>
+                  )}
+                  <FormError id={region.errorId}>{region.error}</FormError>
+                </InputGroup>
+              )}
               <InputGroup>
                 <Label htmlFor={queue.id} variant="small">
                   Queue
@@ -803,6 +867,7 @@ function ScheduledTaskForm({
   templates,
   disableVersionSelection,
   allowArbitraryQueues,
+  regions,
 }: {
   task: ScheduledTaskResult["task"];
   runs: ScheduledRun[];
@@ -812,6 +877,7 @@ function ScheduledTaskForm({
   templates: RunTemplate[];
   disableVersionSelection: boolean;
   allowArbitraryQueues: boolean;
+  regions: Region[];
 }) {
   const environment = useEnvironment();
 
@@ -833,6 +899,12 @@ function ScheduledTaskForm({
   );
   const [queueValue, setQueueValue] = useState<string | undefined>(lastRun?.queue);
   const [machineValue, setMachineValue] = useState<string | undefined>(lastRun?.machinePreset);
+  const isDev = environment.type === "DEVELOPMENT";
+  const defaultRegion = regions.find((r) => r.isDefault);
+  const [regionValue, setRegionValue] = useState<string | undefined>(
+    isDev ? undefined : defaultRegion?.name
+  );
+
   const [maxAttemptsValue, setMaxAttemptsValue] = useState<number | undefined>(
     lastRun?.maxAttempts
   );
@@ -843,6 +915,12 @@ function ScheduledTaskForm({
 
   const [showTemplateCreatedSuccessMessage, setShowTemplateCreatedSuccessMessage] = useState(false);
 
+  const regionItems = regions.map((r) => ({
+    value: r.name,
+    label: r.description ? `${r.name} — ${r.description}` : r.name,
+    isDefault: r.isDefault,
+  }));
+
   const queueItems = queues.map((q) => ({
     value: q.type === "task" ? `task/${q.name}` : q.name,
     label: q.name,
@@ -879,6 +957,7 @@ function ScheduledTaskForm({
       tags,
       version,
       machine,
+      region,
       prioritySeconds,
     },
   ] = useForm({
@@ -1101,6 +1180,45 @@ function ScheduledTaskForm({
             )}
             <FormError id={version.errorId}>{version.error}</FormError>
           </InputGroup>
+          {regionItems.length > 1 && (
+            <InputGroup>
+              <Label htmlFor={region.id} variant="small">
+                Region
+              </Label>
+              {/* Our Select primitive uses Ariakit under the hood, which treats
+                  value={undefined} as uncontrolled, keeping stale internal state when
+                  switching environments. The key forces a remount so it reinitializes
+                  with the correct defaultValue. */}
+              <Select
+                key={`region-${environment.id}`}
+                {...conform.select(region)}
+                variant="tertiary/small"
+                placeholder={isDev ? "–" : undefined}
+                dropdownIcon
+                items={regionItems}
+                defaultValue={isDev ? undefined : defaultRegion?.name}
+                value={isDev ? undefined : regionValue}
+                setValue={isDev ? undefined : (e) => {
+                  if (Array.isArray(e)) return;
+                  setRegionValue(e);
+                }}
+                disabled={isDev}
+              >
+                {regionItems.map((r) => (
+                  <SelectItem key={r.value} value={r.value}>
+                    {r.label}
+                    {r.isDefault ? " (default)" : ""}
+                  </SelectItem>
+                ))}
+              </Select>
+              {isDev ? (
+                <Hint>Region is not available in the development environment.</Hint>
+              ) : (
+                <Hint>Overrides the region for this run.</Hint>
+              )}
+              <FormError id={region.errorId}>{region.error}</FormError>
+            </InputGroup>
+          )}
           <InputGroup>
             <Label htmlFor={queue.id} variant="small">
               Queue
diff --git a/apps/webapp/app/routes/resources.taskruns.$runParam.replay.ts b/apps/webapp/app/routes/resources.taskruns.$runParam.replay.ts
index 5448a99483b..eba924f409b 100644
--- a/apps/webapp/app/routes/resources.taskruns.$runParam.replay.ts
+++ b/apps/webapp/app/routes/resources.taskruns.$runParam.replay.ts
@@ -7,7 +7,7 @@ import { $replica, prisma } from "~/db.server";
 import { redirectWithErrorMessage, redirectWithSuccessMessage } from "~/models/message.server";
 import { displayableEnvironment } from "~/models/runtimeEnvironment.server";
 import { logger } from "~/services/logger.server";
-import { requireUserId } from "~/services/session.server";
+import { requireUser } from "~/services/session.server";
 import { sortEnvironments } from "~/utils/environmentSort";
 import { v3RunSpanPath } from "~/utils/pathBuilder";
 import { ReplayTaskRunService } from "~/v3/services/replayTaskRun.server";
@@ -15,6 +15,7 @@ import parseDuration from "parse-duration";
 import { findCurrentWorkerDeployment } from "~/v3/models/workerDeployment.server";
 import { queueTypeFromType } from "~/presenters/v3/QueueRetrievePresenter.server";
 import { ReplayRunData } from "~/v3/replayTask";
+import { RegionsPresenter } from "~/presenters/v3/RegionsPresenter.server";
 
 const ParamSchema = z.object({
   runParam: z.string(),
@@ -25,7 +26,8 @@ const QuerySchema = z.object({
 });
 
 export async function loader({ request, params }: LoaderFunctionArgs) {
-  const userId = await requireUserId(request);
+  const user = await requireUser(request);
+  const userId = user.id;
   const { runParam } = ParamSchema.parse(params);
   const { environmentIdOverride } = QuerySchema.parse(
     Object.fromEntries(new URL(request.url).searchParams)
@@ -42,6 +44,7 @@ export async function loader({ request, params }: LoaderFunctionArgs) {
       maxAttempts: true,
       maxDurationInSeconds: true,
       machinePreset: true,
+      workerQueue: true,
       ttl: true,
       idempotencyKey: true,
       runTags: true,
@@ -49,6 +52,7 @@ export async function loader({ request, params }: LoaderFunctionArgs) {
       taskIdentifier: true,
       project: {
         select: {
+          slug: true,
           environments: {
             select: {
               id: true,
@@ -108,13 +112,22 @@ export async function loader({ request, params }: LoaderFunctionArgs) {
   const disableVersionSelection = environment.type === "DEVELOPMENT";
   const allowArbitraryQueues = backgroundWorkers.at(0)?.engine === "V1";
 
-  const payload = await prettyPrintPacket(run.payload, run.payloadType);
+  const [payload, regionsResult] = await Promise.all([
+    prettyPrintPacket(run.payload, run.payloadType),
+    new RegionsPresenter().call({
+      userId,
+      projectSlug: run.project.slug,
+      isAdmin: user.admin || user.isImpersonating,
+    }),
+  ]);
 
   return typedjson({
     concurrencyKey: run.concurrencyKey,
     maxAttempts: run.maxAttempts,
     maxDurationSeconds: run.maxDurationInSeconds,
     machinePreset: run.machinePreset,
+    region: environment.type === "DEVELOPMENT" ? undefined : run.workerQueue,
+    regions: regionsResult.regions,
     ttlSeconds: run.ttl ? parseDuration(run.ttl, "s") ?? undefined : undefined,
     idempotencyKey: run.idempotencyKey,
     runTags: run.runTags,
@@ -194,6 +207,7 @@ export const action: ActionFunction = async ({ request, params }) => {
       maxAttempts: submission.value.maxAttempts,
       maxDurationSeconds: submission.value.maxDurationSeconds,
       machine: submission.value.machine,
+      region: submission.value.region,
       delaySeconds: submission.value.delaySeconds,
       idempotencyKey: submission.value.idempotencyKey,
       idempotencyKeyTTLSeconds: submission.value.idempotencyKeyTTLSeconds,
diff --git a/apps/webapp/app/v3/services/replayTaskRun.server.ts b/apps/webapp/app/v3/services/replayTaskRun.server.ts
index ceaae95398f..a5018f51c57 100644
--- a/apps/webapp/app/v3/services/replayTaskRun.server.ts
+++ b/apps/webapp/app/v3/services/replayTaskRun.server.ts
@@ -64,7 +64,7 @@ export class ReplayTaskRunService extends BaseService {
       existingTaskRun.engine === "V1" ||
       existingEnvironment.type === "DEVELOPMENT" ||
       authenticatedEnvironment.type === "DEVELOPMENT";
-    const region = ignoreRegion ? undefined : existingTaskRun.workerQueue;
+    const region = ignoreRegion ? undefined : overrideOptions.region ?? existingTaskRun.workerQueue;
 
     try {
       const taskQueue = await this._prisma.taskQueue.findFirst({
diff --git a/apps/webapp/app/v3/services/testTask.server.ts b/apps/webapp/app/v3/services/testTask.server.ts
index d999fed0464..0b64367f600 100644
--- a/apps/webapp/app/v3/services/testTask.server.ts
+++ b/apps/webapp/app/v3/services/testTask.server.ts
@@ -28,6 +28,7 @@ export class TestTaskService extends BaseService {
             maxDuration: data.maxDurationSeconds,
             tags: data.tags,
             machine: data.machine,
+            region: data.region,
             lockToVersion: data.version === "latest" ? undefined : data.version,
             priority: data.prioritySeconds,
           },
@@ -66,6 +67,7 @@ export class TestTaskService extends BaseService {
               maxDuration: data.maxDurationSeconds,
               tags: data.tags,
               machine: data.machine,
+              region: data.region,
               lockToVersion: data.version === "latest" ? undefined : data.version,
               priority: data.prioritySeconds,
             },
diff --git a/apps/webapp/app/v3/testTask.ts b/apps/webapp/app/v3/testTask.ts
index bf167ed1702..54db301cdef 100644
--- a/apps/webapp/app/v3/testTask.ts
+++ b/apps/webapp/app/v3/testTask.ts
@@ -22,6 +22,7 @@ export const RunOptionsData = z.object({
   concurrencyKey: z.string().optional(),
   maxAttempts: z.number().min(1).optional(),
   machine: MachinePresetName.optional(),
+  region: z.string().optional(),
   maxDurationSeconds: z
     .number()
     .min(0)