diff --git a/.changeset/custom-dashboard-port.md b/.changeset/custom-dashboard-port.md
new file mode 100644
index 0000000..5d8f6f3
--- /dev/null
+++ b/.changeset/custom-dashboard-port.md
@@ -0,0 +1,5 @@
+---
+"@openworkflow/cli": patch
+---
+
+Add a `--port` option to `openworkflow dashboard` so users can run the dashboard server on a custom port.
diff --git a/packages/cli/cli.ts b/packages/cli/cli.ts
index 009e491..228fd75 100644
--- a/packages/cli/cli.ts
+++ b/packages/cli/cli.ts
@@ -51,6 +51,11 @@ workerCmd
 program
   .command("dashboard")
   .description("start the dashboard to view workflow runs")
+  .option(
+    "-p, --port <number>",
+    "custom port for the dashboard server",
+    Number.parseInt,
+  )
   .option("--config <path>", "path to OpenWorkflow config file")
   .action(withErrorHandling(dashboard));
 
diff --git a/packages/cli/commands.test.ts b/packages/cli/commands.test.ts
index f7f0ad4..4176cf7 100644
--- a/packages/cli/commands.test.ts
+++ b/packages/cli/commands.test.ts
@@ -1,9 +1,11 @@
 import {
   discoverWorkflowFiles,
+  getDashboardSpawnOptions,
   getClientFileName,
   getConfigFileName,
   getExampleWorkflowFileName,
   getRunFileName,
+  validateDashboardPort,
 } from "./commands.js";
 import fs from "node:fs";
 import os from "node:os";
@@ -141,3 +143,49 @@ describe("discoverWorkflowFiles", () => {
     }
   });
 });
+
+describe("getDashboardSpawnOptions", () => {
+  test("uses default npx command without a custom port env", () => {
+    const options = getDashboardSpawnOptions();
+
+    expect(options.command).toBe("npx");
+    expect(options.args).toEqual(["@openworkflow/dashboard"]);
+    expect(options.spawnOptions.env?.["PORT"]).toBeUndefined();
+    expect(options.spawnOptions.stdio).toBe("inherit");
+  });
+
+  test("sets PORT env when a custom dashboard port is provided", () => {
+    const options = getDashboardSpawnOptions(4321);
+
+    expect(options.command).toBe("npx");
+    expect(options.args).toEqual(["@openworkflow/dashboard"]);
+    expect(options.spawnOptions.env?.["PORT"]).toBe("4321");
+    expect(options.spawnOptions.stdio).toBe("inherit");
+  });
+});
+
+describe("validateDashboardPort", () => {
+  test("returns undefined when no custom port is provided", () => {
+    expect(validateDashboardPort()).toBeUndefined();
+  });
+
+  test("returns the port when it is within range", () => {
+    expect(validateDashboardPort(3001)).toBe(3001);
+  });
+
+  test("throws for non-integer ports", () => {
+    expect(() => validateDashboardPort(Number.NaN)).toThrow(
+      "Invalid dashboard port.",
+    );
+    expect(() => validateDashboardPort(3000.5)).toThrow(
+      "Invalid dashboard port.",
+    );
+  });
+
+  test("throws for out-of-range ports", () => {
+    expect(() => validateDashboardPort(0)).toThrow("Invalid dashboard port.");
+    expect(() => validateDashboardPort(65_536)).toThrow(
+      "Invalid dashboard port.",
+    );
+  });
+});
diff --git a/packages/cli/commands.ts b/packages/cli/commands.ts
index 9da3bd6..eb89a47 100644
--- a/packages/cli/commands.ts
+++ b/packages/cli/commands.ts
@@ -35,6 +35,10 @@ interface CommandOptions {
   config?: string;
 }
 
+interface DashboardOptions extends CommandOptions {
+  port?: number;
+}
+
 /**
  * openworkflow -V | --version
  * @returns the version string, or "-" if it cannot be determined
@@ -340,10 +344,59 @@ export async function workerStart(
 /**
  * openworkflow dashboard
  * Starts the dashboard by delegating to `@openworkflow/dashboard` via npx.
- * @param options - Command options
+ * @param port - Optional dashboard port.
+ * @returns Spawn configuration for launching the dashboard process.
+ */
+export function getDashboardSpawnOptions(port?: number): {
+  command: string;
+  args: string[];
+  spawnOptions: {
+    stdio: "inherit";
+    env?: NodeJS.ProcessEnv;
+  };
+} {
+  return {
+    command: "npx",
+    args: ["@openworkflow/dashboard"],
+    spawnOptions: {
+      stdio: "inherit",
+      env:
+        port === undefined
+          ? process.env
+          : { ...process.env, PORT: String(port) },
+    },
+  };
+}
+
+/**
+ * Validate dashboard port option.
+ * @param port - Optional dashboard port.
+ * @returns Validated dashboard port.
+ * @throws {CLIError} If the provided port is not an integer in the 1-65535 range.
  */
-export async function dashboard(options: CommandOptions = {}): Promise<void> {
+export function validateDashboardPort(port?: number): number | undefined {
+  if (port === undefined) {
+    return undefined;
+  }
+
+  if (!Number.isInteger(port) || port < 1 || port > 65_535) {
+    throw new CLIError(
+      "Invalid dashboard port.",
+      "Use an integer between 1 and 65535, for example `--port 3001`.",
+    );
+  }
+
+  return port;
+}
+
+/**
+ * Start the dashboard process.
+ * @param options - Dashboard command options.
+ * @returns Resolves when the dashboard process exits.
+ */
+export async function dashboard(options: DashboardOptions = {}): Promise<void> {
   const configPath = options.config;
+  const port = validateDashboardPort(options.port);
   consola.start("Starting dashboard...");
 
   const { configFile } = await loadConfigWithEnv(configPath);
@@ -355,10 +408,12 @@ export async function dashboard(options: CommandOptions = {}): Promise<void> {
   }
   consola.info(`Using config: ${configFile}`);
 
-  // eslint-disable-next-line sonarjs/no-os-command-from-path
-  const child = spawn("npx", ["@openworkflow/dashboard"], {
-    stdio: "inherit",
-  });
+  const spawnConfig = getDashboardSpawnOptions(port);
+  const child = spawn(
+    spawnConfig.command,
+    spawnConfig.args,
+    spawnConfig.spawnOptions,
+  );
 
   await new Promise<void>((resolve, reject) => {
     /** remove signal handlers after the child exits */
diff --git a/packages/docs/docs/cli.mdx b/packages/docs/docs/cli.mdx
index ae49225..fb45bb3 100644
--- a/packages/docs/docs/cli.mdx
+++ b/packages/docs/docs/cli.mdx
@@ -124,8 +124,26 @@ bunx @openworkflow/cli dashboard
 
 </CodeGroup>
 
-This launches the OpenWorkflow dashboard on `http://localhost:3000`. See
-[Dashboard](/docs/dashboard) for details.
+The dashboard starts on `http://localhost:3000` by default.
+
+To use a custom port:
+
+<CodeGroup>
+```bash npm
+npx @openworkflow/cli dashboard --port 4000
+```
+
+```bash pnpm
+pnpx @openworkflow/cli dashboard --port 4000
+```
+
+```bash bun
+bunx @openworkflow/cli dashboard --port 4000
+```
+
+</CodeGroup>
+
+See [Dashboard](/docs/dashboard) for details.
 
 ### `doctor`
 
diff --git a/packages/docs/docs/dashboard.mdx b/packages/docs/docs/dashboard.mdx
index e3f9844..43417f5 100644
--- a/packages/docs/docs/dashboard.mdx
+++ b/packages/docs/docs/dashboard.mdx
@@ -24,7 +24,24 @@ bunx @openworkflow/cli dashboard
 
 </CodeGroup>
 
-The dashboard starts on `http://localhost:3000`.
+The dashboard starts on `http://localhost:3000` by default.
+
+To use a custom port:
+
+<CodeGroup>
+```bash npm
+npx @openworkflow/cli dashboard --port 4000
+```
+
+```bash pnpm
+pnpx @openworkflow/cli dashboard --port 4000
+```
+
+```bash bun
+bunx @openworkflow/cli dashboard --port 4000
+```
+
+</CodeGroup>
 
 ## Requirements