diff --git a/pkg/models/admin_project_list.go b/pkg/models/admin_project_list.go
new file mode 100644
index 000000000..fe7e08277
--- /dev/null
+++ b/pkg/models/admin_project_list.go
@@ -0,0 +1,69 @@
+// Vikunja is a to-do list application to facilitate your life.
+// Copyright 2018-present Vikunja and contributors. All rights reserved.
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Affero General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU Affero General Public License for more details.
+//
+// You should have received a copy of the GNU Affero General Public License
+// along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+package models
+
+import (
+	"code.vikunja.io/api/pkg/user"
+	"code.vikunja.io/api/pkg/web"
+
+	"xorm.io/xorm"
+)
+
+// AdminProjectList overrides ReadAll to return every project on the instance;
+// non-ReadAll methods inherit from Project and are gated by RequireInstanceAdmin.
+type AdminProjectList struct {
+	Project
+}
+
+// ReassignProjectOwner refuses owners scheduled for deletion because DeleteUser cascades to their projects.
+func ReassignProjectOwner(s *xorm.Session, projectID, newOwnerID int64) (*Project, error) {
+	p, err := GetProjectSimpleByID(s, projectID)
+	if err != nil {
+		return nil, err
+	}
+
+	newOwner, err := user.GetUserByID(s, newOwnerID)
+	if err != nil {
+		return nil, err
+	}
+	if !newOwner.DeletionScheduledAt.IsZero() {
+		return nil, ErrInvalidData{Message: "new owner is scheduled for deletion"}
+	}
+
+	p.OwnerID = newOwnerID
+	if _, err := s.ID(p.ID).Cols("owner_id").Update(p); err != nil {
+		return nil, err
+	}
+	p.Owner = newOwner
+	return p, nil
+}
+
+// ReadAll returns every project on the instance, archived included.
+// @Summary List projects (admin)
+// @Description Paginated list of every project on the instance, regardless of ownership.
+// @tags admin
+// @Produce json
+// @Security JWTKeyAuth
+// @Param page query int false "Page number, defaults to 1."
+// @Param per_page query int false "Items per page, defaults to the service setting."
+// @Param s query string false "Search projects by title, description or identifier."
+// @Success 200 {array} models.Project
+// @Failure 404 {object} web.HTTPError
+// @Router /admin/projects [get]
+func (l *AdminProjectList) ReadAll(s *xorm.Session, _ web.Auth, search string, page, perPage int) (interface{}, int, int64, error) {
+	return ListAllProjects(s, search, page, perPage, true)
+}
diff --git a/pkg/routes/api/v1/admin/projects.go b/pkg/routes/api/v1/admin/projects.go
new file mode 100644
index 000000000..9571c8d63
--- /dev/null
+++ b/pkg/routes/api/v1/admin/projects.go
@@ -0,0 +1,67 @@
+// Vikunja is a to-do list application to facilitate your life.
+// Copyright 2018-present Vikunja and contributors. All rights reserved.
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Affero General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU Affero General Public License for more details.
+//
+// You should have received a copy of the GNU Affero General Public License
+// along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+package admin
+
+import (
+	"net/http"
+	"strconv"
+
+	"code.vikunja.io/api/pkg/db"
+	"code.vikunja.io/api/pkg/models"
+	"github.com/labstack/echo/v5"
+)
+
+type OwnerPatch struct {
+	OwnerID int64 `json:"owner_id"`
+}
+
+// PatchProjectOwner reassigns a project's owner.
+// @Summary Reassign project owner (admin)
+// @Description Reassign a project's owner. The existing update endpoint doesn't allow owner changes — this is the admin-only escape hatch.
+// @tags admin
+// @Accept json
+// @Produce json
+// @Security JWTKeyAuth
+// @Param id path int true "Project ID"
+// @Param body body admin.OwnerPatch true "New owner"
+// @Success 200 {object} models.Project
+// @Failure 400 {object} web.HTTPError
+// @Failure 404 {object} web.HTTPError
+// @Router /admin/projects/{id}/owner [patch]
+func PatchProjectOwner(c *echo.Context) error {
+	id, err := strconv.ParseInt(c.Param("id"), 10, 64)
+	if err != nil || id < 1 {
+		return models.ErrProjectDoesNotExist{ID: id}
+	}
+
+	body := &OwnerPatch{}
+	if err := c.Bind(body); err != nil || body.OwnerID < 1 {
+		return models.ErrInvalidData{Message: "invalid body"}
+	}
+
+	s := db.NewSession()
+	defer s.Close()
+
+	p, err := models.ReassignProjectOwner(s, id, body.OwnerID)
+	if err != nil {
+		return err
+	}
+	if err := s.Commit(); err != nil {
+		return err
+	}
+	return c.JSON(http.StatusOK, p)
+}
diff --git a/pkg/routes/api/v1/admin/users.go b/pkg/routes/api/v1/admin/users.go
new file mode 100644
index 000000000..f9392b772
--- /dev/null
+++ b/pkg/routes/api/v1/admin/users.go
@@ -0,0 +1,116 @@
+// Vikunja is a to-do list application to facilitate your life.
+// Copyright 2018-present Vikunja and contributors. All rights reserved.
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Affero General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU Affero General Public License for more details.
+//
+// You should have received a copy of the GNU Affero General Public License
+// along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+package admin
+
+import (
+	"code.vikunja.io/api/pkg/modules/auth/openid"
+	"code.vikunja.io/api/pkg/user"
+	"code.vikunja.io/api/pkg/web"
+
+	"xorm.io/xorm"
+)
+
+// User re-exposes fields hidden by the default user.User JSON view.
+type User struct {
+	*user.User
+	IsAdmin      bool        `json:"is_admin"`
+	Status       user.Status `json:"status"`
+	Issuer       string      `json:"issuer"`
+	Subject      string      `json:"subject,omitempty"`
+	AuthProvider string      `json:"auth_provider,omitempty"`
+}
+
+func newAdminUser(u *user.User, providers []*openid.Provider) *User {
+	return &User{
+		User:         u,
+		IsAdmin:      u.IsAdmin,
+		Status:       u.Status,
+		Issuer:       u.Issuer,
+		Subject:      u.Subject,
+		AuthProvider: resolveAuthProvider(u, providers),
+	}
+}
+
+func resolveAuthProvider(u *user.User, providers []*openid.Provider) string {
+	switch u.Issuer {
+	case "", user.IssuerLocal:
+		return ""
+	case user.IssuerLDAP:
+		return "LDAP"
+	}
+	for _, provider := range providers {
+		issuerURL, err := provider.Issuer()
+		if err != nil {
+			continue
+		}
+		if issuerURL == u.Issuer {
+			return provider.Name
+		}
+	}
+	return u.Issuer
+}
+
+// UserList backs the admin list-users route via handler.ReadAllWeb; only ReadAll is used.
+type UserList struct {
+	web.CRUDable    `xorm:"-" json:"-"`
+	web.Permissions `xorm:"-" json:"-"`
+}
+
+// ReadAll returns paginated users, optionally filtered by username/email.
+// @Summary List users (admin)
+// @Description Paginated list of all users on the instance. Supports search by username/email. Exposes fields hidden from the normal user API (is_admin, status).
+// @tags admin
+// @Produce json
+// @Security JWTKeyAuth
+// @Param s query string false "Search string matched against username and email."
+// @Param page query int false "Page number, defaults to 1."
+// @Param per_page query int false "Items per page, defaults to the service setting."
+// @Success 200 {array} admin.User
+// @Failure 404 {object} web.HTTPError
+// @Router /admin/users [get]
+func (*UserList) ReadAll(s *xorm.Session, _ web.Auth, search string, page, perPage int) (interface{}, int, int64, error) {
+	finder := s.Limit(perPage, (page-1)*perPage).OrderBy("id ASC")
+	counter := s
+	if search != "" {
+		q := "%" + search + "%"
+		finder = finder.Where("username LIKE ? OR email LIKE ?", q, q)
+		counter = s.Where("username LIKE ? OR email LIKE ?", q, q)
+	}
+
+	var users []*user.User
+	if err := finder.Find(&users); err != nil {
+		return nil, 0, 0, err
+	}
+
+	totalCount, err := counter.Count(&user.User{})
+	if err != nil {
+		return nil, 0, 0, err
+	}
+
+	providers, err := openid.GetAllProviders()
+	if err != nil {
+		return nil, 0, 0, err
+	}
+
+	out := make([]*User, 0, len(users))
+	for _, u := range users {
+		out = append(out, newAdminUser(u, providers))
+	}
+	return out, len(out), totalCount, nil
+}
+
+func (*UserList) CanRead(*xorm.Session, web.Auth) (bool, int, error) { return true, 0, nil }
diff --git a/pkg/routes/api/v1/admin/users_admin.go b/pkg/routes/api/v1/admin/users_admin.go
new file mode 100644
index 000000000..5f31b269f
--- /dev/null
+++ b/pkg/routes/api/v1/admin/users_admin.go
@@ -0,0 +1,96 @@
+// Vikunja is a to-do list application to facilitate your life.
+// Copyright 2018-present Vikunja and contributors. All rights reserved.
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Affero General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU Affero General Public License for more details.
+//
+// You should have received a copy of the GNU Affero General Public License
+// along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+package admin
+
+import (
+	"net/http"
+	"strconv"
+
+	"code.vikunja.io/api/pkg/db"
+	"code.vikunja.io/api/pkg/models"
+	"code.vikunja.io/api/pkg/modules/auth/openid"
+	"code.vikunja.io/api/pkg/user"
+	"github.com/labstack/echo/v5"
+)
+
+type IsAdminPatch struct {
+	// Pointer to distinguish "omitted" from false; an empty body would silently demote otherwise.
+	IsAdmin *bool `json:"is_admin"`
+}
+
+// PatchAdmin toggles a user's instance-admin flag.
+// @Summary Promote or demote a user (admin)
+// @Description Toggle the instance-admin flag on a user. Demoting the last remaining admin is refused with 400.
+// @tags admin
+// @Accept json
+// @Produce json
+// @Security JWTKeyAuth
+// @Param id path int true "User ID"
+// @Param body body admin.IsAdminPatch true "New admin value"
+// @Success 200 {object} admin.User
+// @Failure 400 {object} web.HTTPError
+// @Failure 404 {object} web.HTTPError
+// @Router /admin/users/{id}/admin [patch]
+func PatchAdmin(c *echo.Context) error {
+	idStr := c.Param("id")
+	id, err := strconv.ParseInt(idStr, 10, 64)
+	if err != nil || id < 1 {
+		return user.ErrUserDoesNotExist{UserID: id}
+	}
+
+	body := &IsAdminPatch{}
+	if err := c.Bind(body); err != nil {
+		return models.ErrInvalidData{Message: "invalid body"}
+	}
+	if body.IsAdmin == nil {
+		return models.ErrInvalidData{Message: "is_admin is required"}
+	}
+
+	s := db.NewSession()
+	defer s.Close()
+
+	target := &user.User{ID: id}
+	has, err := s.Get(target)
+	if err != nil {
+		return err
+	}
+	if !has {
+		return user.ErrUserDoesNotExist{UserID: id}
+	}
+
+	if !*body.IsAdmin {
+		if err := user.GuardLastAdmin(s, target); err != nil {
+			_ = s.Rollback()
+			return err
+		}
+	}
+
+	target.IsAdmin = *body.IsAdmin
+	if _, err := s.ID(target.ID).Cols("is_admin").Update(target); err != nil {
+		_ = s.Rollback()
+		return err
+	}
+	if err := s.Commit(); err != nil {
+		return err
+	}
+
+	providers, err := openid.GetAllProviders()
+	if err != nil {
+		return err
+	}
+	return c.JSON(http.StatusOK, newAdminUser(target, providers))
+}