diff --git a/API.md b/API.md
index 89db016..5b54dd5 100644
--- a/API.md
+++ b/API.md
@@ -77,6 +77,10 @@
 - `POST /api/activities/:id/dependencies` · `DELETE /api/activities/:id/dependencies/:dependsOnId`
 - `PUT /api/projects/:projectId/activities/reorder` — `{ ids: [...] }` (orden manual, arrastrar
   con el mouse); posiciones 1..N, nunca 0 (0 = "nunca reordenado a mano", ver `sort_order`).
+- `PUT /api/activities/:id/move` — `{ projectId }`. Mueve la actividad a otro proyecto; exige
+  permiso de escritura en ambos proyectos. Tareas/comentarios/adjuntos se mueven solos (referencian
+  `activity_id`, no `project_id`). Las dependencias existentes (en cualquiera de los dos sentidos)
+  se eliminan — solo tienen sentido dentro del mismo proyecto. `sort_order` vuelve a 0 en el destino.
 
 ### Tareas (`/api/activities/:activityId/tasks`)
 - `GET` · `POST` · `PUT /api/tasks/:id` · `PATCH /api/tasks/:id/done` · `DELETE /api/tasks/:id`
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 873edcf..cf25894 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,14 @@
 # Changelog - project.linkedcorp.net
 
+## [1.17.0] - 2026-09-16
+### Added
+- Mover una actividad a otro proyecto (menú de tres puntos en el listado de Actividades): se
+  eligen el proyecto destino y se confirma con un mensaje ("Se moverá la actividad "X" (junto con
+  sus tareas) al proyecto "Y". ¿Deseas continuar?", Aceptar/Cancelar) antes de ejecutar. Tareas,
+  comentarios y adjuntos se mueven solos (referencian la actividad, no el proyecto). Las
+  dependencias existentes se eliminan al mover (solo tienen sentido dentro del mismo proyecto).
+  Nuevo `PUT /api/activities/:id/move`, exige permiso de escritura en ambos proyectos.
+
 ## [1.16.4] - 2026-09-16
 ### Added
 - Columna "Actualizado" (fecha y hora) en el listado de Actividades de un proyecto — mismo
diff --git a/VERSION b/VERSION
index a232073..092afa1 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-1.16.4
+1.17.0
diff --git a/backend/package.json b/backend/package.json
index 04f1255..29d30cd 100644
--- a/backend/package.json
+++ b/backend/package.json
@@ -1,6 +1,6 @@
 {
   "name": "project-linkedcorp-backend",
-  "version": "1.16.4",
+  "version": "1.17.0",
   "private": true,
   "type": "module",
   "main": "src/server.js",
diff --git a/backend/src/modules/activities/controller.js b/backend/src/modules/activities/controller.js
index ae961a3..fefbd59 100644
--- a/backend/src/modules/activities/controller.js
+++ b/backend/src/modules/activities/controller.js
@@ -26,6 +26,10 @@ export const deleteActivity = asyncHandler(async (req, res) => {
   ok(res, { deleted: true });
 });
 
+export const putMoveActivity = asyncHandler(async (req, res) => {
+  ok(res, await service.moveActivity(Number(req.params.id), Number(req.body.projectId), req.currentUser));
+});
+
 export const postDependency = asyncHandler(async (req, res) => {
   const deps = await service.addDependency(Number(req.params.id), Number(req.body.dependsOnActivityId), req.currentUser);
   ok(res, deps, 201);
diff --git a/backend/src/modules/activities/repository.js b/backend/src/modules/activities/repository.js
index 4a22520..784c261 100644
--- a/backend/src/modules/activities/repository.js
+++ b/backend/src/modules/activities/repository.js
@@ -64,6 +64,17 @@ export async function remove(id) {
   await pool.query('DELETE FROM activities WHERE id = ?', [id]);
 }
 
+// Las tareas (tasks.activity_id) y los comentarios/adjuntos (entity_id de la actividad) se
+// "mueven" solos, sin tocar nada — no referencian project_id. sort_order vuelve a 0 ("nunca
+// reordenado a mano") para que aparezca al final del proyecto destino sin pisar su orden manual.
+// Las dependencias solo tienen sentido dentro del mismo proyecto (addDependency ya lo exige), asi
+// que las existentes (en cualquiera de los dos sentidos) quedan invalidas al cambiar de proyecto.
+export async function moveToProject(id, projectId) {
+  await pool.query('UPDATE activities SET project_id = ?, sort_order = 0 WHERE id = ?', [projectId, id]);
+  await pool.query('DELETE FROM activity_dependencies WHERE activity_id = ? OR depends_on_activity_id = ?', [id, id]);
+  return findById(id);
+}
+
 // Posiciones SIEMPRE 1..N (nunca 0 — 0 queda reservado para "nunca reordenado a mano" en la
 // migracion). Solo reordena las filas de projectId que vengan en ids, ignora el resto.
 export async function reorder(projectId, ids) {
diff --git a/backend/src/modules/activities/routes.js b/backend/src/modules/activities/routes.js
index 99e4262..7b79c40 100644
--- a/backend/src/modules/activities/routes.js
+++ b/backend/src/modules/activities/routes.js
@@ -1,6 +1,6 @@
 import { Router } from 'express';
 import { requireAuth } from '../../middleware/auth.js';
-import { getActivity, putActivity, deleteActivity, postDependency, deleteDependency } from './controller.js';
+import { getActivity, putActivity, deleteActivity, putMoveActivity, postDependency, deleteDependency } from './controller.js';
 
 const router = Router();
 
@@ -8,6 +8,7 @@ router.use(requireAuth);
 router.get('/:id', getActivity);
 router.put('/:id', putActivity);
 router.delete('/:id', deleteActivity);
+router.put('/:id/move', putMoveActivity);
 router.post('/:id/dependencies', postDependency);
 router.delete('/:id/dependencies/:dependsOnId', deleteDependency);
 
diff --git a/backend/src/modules/activities/service.js b/backend/src/modules/activities/service.js
index 6a46404..b841423 100644
--- a/backend/src/modules/activities/service.js
+++ b/backend/src/modules/activities/service.js
@@ -118,6 +118,32 @@ export async function removeActivity(id, currentUser) {
   await recalcProjectProgress(activity.project_id);
 }
 
+// Mueve la actividad (y sus tareas/comentarios/adjuntos, que van solos por referenciar activity_id
+// en vez de project_id) a otro proyecto. Exige permiso de escritura en AMBOS proyectos.
+export async function moveActivity(id, targetProjectId, currentUser) {
+  const activity = await repo.findById(id);
+  if (!activity) throw new HttpError(404, 'Actividad no encontrada');
+  const sourceProject = await getProjectOr404(activity.project_id);
+  if (!(await canWriteActivity(currentUser, sourceProject, activity))) {
+    throw new HttpError(403, 'No tienes permisos sobre esta actividad');
+  }
+  if (Number(targetProjectId) === activity.project_id) {
+    throw new HttpError(400, 'La actividad ya pertenece a este proyecto');
+  }
+  const targetProject = await getProjectOr404(targetProjectId);
+  if (!(await canWriteProject(currentUser, targetProject))) {
+    throw new HttpError(403, 'No tienes permisos sobre el proyecto de destino');
+  }
+  const moved = await repo.moveToProject(id, targetProjectId);
+  await logAudit({
+    userId: currentUser.id, action: 'move', entityType: 'activity', entityId: id,
+    detail: { fromProjectId: activity.project_id, toProjectId: Number(targetProjectId) },
+  });
+  await recalcProjectProgress(activity.project_id);
+  await recalcProjectProgress(targetProjectId);
+  return moved;
+}
+
 // Nuevo orden manual (arrastrar con el mouse): mismo permiso que crear actividades en el proyecto.
 export async function reorderActivities(projectId, ids, currentUser) {
   const project = await getProjectOr404(projectId);
diff --git a/frontend/package.json b/frontend/package.json
index 2edc249..64326ce 100644
--- a/frontend/package.json
+++ b/frontend/package.json
@@ -1,7 +1,7 @@
 {
   "name": "project-linkedcorp-frontend",
   "private": true,
-  "version": "1.16.4",
+  "version": "1.17.0",
   "type": "module",
   "scripts": {
     "dev": "vite",
diff --git a/frontend/src/i18n/messages.js b/frontend/src/i18n/messages.js
index 6973b88..8dffbe6 100644
--- a/frontend/src/i18n/messages.js
+++ b/frontend/src/i18n/messages.js
@@ -76,6 +76,7 @@ export const messages = {
     common_edit: 'Editar',
     common_save: 'Guardar',
     common_cancel: 'Cancelar',
+    common_accept: 'Aceptar',
     common_delete: 'Eliminar',
     common_close: 'Cerrar',
     common_search: 'Buscar...',
@@ -199,6 +200,10 @@ export const messages = {
     activity_milestone: 'Es hito',
     activity_estimated_hours: 'Horas estimadas',
     activity_dependencies: 'Dependencias',
+    activity_move: 'Mover a otro proyecto',
+    activity_move_title: 'Mover actividad',
+    activity_move_target: 'Proyecto destino',
+    activity_move_confirm_msg: 'Se moverá la actividad "{activity}" (junto con sus tareas) al proyecto "{project}". ¿Deseas continuar?',
     activity_add_dependency: 'Agregar dependencia',
     activity_depends_on: 'Depende de',
     activity_no_dependency_options: 'No hay otras actividades en este proyecto para agregar como dependencia.',
@@ -318,6 +323,7 @@ export const messages = {
     common_edit: 'Edit',
     common_save: 'Save',
     common_cancel: 'Cancel',
+    common_accept: 'Accept',
     common_delete: 'Delete',
     common_close: 'Close',
     common_search: 'Search...',
@@ -441,6 +447,10 @@ export const messages = {
     activity_milestone: 'Is milestone',
     activity_estimated_hours: 'Estimated hours',
     activity_dependencies: 'Dependencies',
+    activity_move: 'Move to another project',
+    activity_move_title: 'Move activity',
+    activity_move_target: 'Target project',
+    activity_move_confirm_msg: 'Activity "{activity}" (along with its tasks) will move to project "{project}". Continue?',
     activity_add_dependency: 'Add dependency',
     activity_depends_on: 'Depends on',
     activity_no_dependency_options: 'There are no other activities in this project to add as a dependency.',
diff --git a/frontend/src/pages/Proyectos/ProjectActivitiesTab.jsx b/frontend/src/pages/Proyectos/ProjectActivitiesTab.jsx
index c9f561c..3487273 100644
--- a/frontend/src/pages/Proyectos/ProjectActivitiesTab.jsx
+++ b/frontend/src/pages/Proyectos/ProjectActivitiesTab.jsx
@@ -1,9 +1,10 @@
 import { useState } from 'react';
-import { Plus, Save, Trash2 } from 'lucide-react';
+import { Plus, Save, Trash2, ArrowRightLeft } from 'lucide-react';
 import { useUi } from '../../context/ui-context.jsx';
 import { useAuth } from '../../context/auth-context.jsx';
 import { useAsync, useAction } from '../../hooks/useAsync.js';
-import { listActivitiesByProject, createActivity, getActivity, deleteActivity, reorderActivities } from '../../services/activities.js';
+import { listActivitiesByProject, createActivity, getActivity, deleteActivity, reorderActivities, moveActivity } from '../../services/activities.js';
+import { listProjects } from '../../services/projects.js';
 import { listCatalog } from '../../services/catalogs.js';
 import { listUsers } from '../../services/users.js';
 import { ListView } from '../../components/ListView.jsx';
@@ -26,15 +27,21 @@ export default function ProjectActivitiesTab({ projectId }) {
   const { data: priorities } = useAsync(() => listCatalog('priorities'), []);
   const { data: statuses } = useAsync(() => listCatalog('activity-statuses'), []);
   const { data: users } = useAsync(listUsers, []);
+  const { data: allProjects } = useAsync(() => listProjects(), []);
 
   const [search, setSearch] = useState('');
   const [creating, setCreating] = useState(false);
   const [form, setForm] = useState(EMPTY_FORM);
   const [selected, setSelected] = useState(null);
+  const [moving, setMoving] = useState(null);
+  const [targetProjectId, setTargetProjectId] = useState('');
 
   const priorityOptions = (priorities || []).map((p) => ({ value: p.id, label: p.name }));
   const statusOptions = (statuses || []).map((s) => ({ value: s.id, label: s.name }));
   const userOptions = (users || []).map((u) => ({ value: u.id, label: u.name }));
+  const projectOptions = (allProjects || [])
+    .filter((p) => p.id !== Number(projectId))
+    .map((p) => ({ value: p.id, label: `${p.code} — ${p.name}` }));
 
   async function save() {
     if (!form.name.trim() || !form.priorityId || !form.statusId) return;
@@ -62,6 +69,34 @@ export default function ProjectActivitiesTab({ projectId }) {
     await reload();
   }
 
+  function startMove(row) {
+    setMoving(row);
+    setTargetProjectId('');
+  }
+
+  function confirmMove() {
+    const target = (allProjects || []).find((p) => p.id === Number(targetProjectId));
+    if (!target) return;
+    const message = t('activity_move_confirm_msg').replace('{activity}', moving.name).replace('{project}', target.name);
+    openDialog({
+      tone: 'warning',
+      title: t('activity_move_title'),
+      message,
+      actions: [
+        { label: t('common_cancel'), variant: 'standard' },
+        {
+          label: t('common_accept'), variant: 'accent',
+          onClick: () => runAction(async () => {
+            await moveActivity(moving.id, Number(targetProjectId));
+            setMoving(null);
+            await reload();
+            pushToast({ tone: 'success', message: t('common_saved') });
+          }),
+        },
+      ],
+    });
+  }
+
   function confirmDelete(row) {
     openDialog({
       tone: 'warning',
@@ -115,10 +150,25 @@ export default function ProjectActivitiesTab({ projectId }) {
         onRowClick={openActivity}
         onReorder={currentUser?.roleCode !== 'viewer' ? handleReorder : undefined}
         rowActions={currentUser?.roleCode !== 'viewer' ? (a) => [
+          { label: t('activity_move'), icon: ArrowRightLeft, onClick: () => startMove(a) },
           { label: t('common_delete'), icon: Trash2, danger: true, onClick: () => confirmDelete(a) },
         ] : undefined}
       />
 
+      <DetailPopup open={!!moving} title={t('activity_move_title')} onClose={() => setMoving(null)} width={480} height={260}>
+        {moving && (
+          <>
+            <Field label={t('activity_move_target')}>
+              <ComboBox options={projectOptions} value={targetProjectId} onChange={setTargetProjectId} />
+            </Field>
+            <div style={{ display: 'flex', gap: 8, marginTop: 12 }}>
+              <Button variant="accent" icon={ArrowRightLeft} onClick={confirmMove} disabled={!targetProjectId}>{t('activity_move')}</Button>
+              <Button variant="standard" onClick={() => setMoving(null)}>{t('common_cancel')}</Button>
+            </div>
+          </>
+        )}
+      </DetailPopup>
+
       <DetailPopup open={creating} title={t('activity_new')} onClose={() => setCreating(false)} width={640} height={560}>
         <Field label={t('common_name')}>
           <input className="input" value={form.name} onChange={(e) => setForm((f) => ({ ...f, name: e.target.value }))} autoFocus />
diff --git a/frontend/src/services/activities.js b/frontend/src/services/activities.js
index 7cc2467..cb5c335 100644
--- a/frontend/src/services/activities.js
+++ b/frontend/src/services/activities.js
@@ -5,6 +5,7 @@ export const createActivity = (projectId, data) => api.post(`/projects/${project
 export const getActivity = (id) => api.get(`/activities/${id}`);
 export const updateActivity = (id, data) => api.put(`/activities/${id}`, data);
 export const deleteActivity = (id) => api.delete(`/activities/${id}`);
+export const moveActivity = (id, projectId) => api.put(`/activities/${id}/move`, { projectId });
 export const reorderActivities = (projectId, ids) => api.put(`/projects/${projectId}/activities/reorder`, { ids });
 export const addDependency = (id, dependsOnActivityId) => api.post(`/activities/${id}/dependencies`, { dependsOnActivityId });
 export const removeDependency = (id, dependsOnId) => api.delete(`/activities/${id}/dependencies/${dependsOnId}`);