diff --git a/modules/git/commit.go b/modules/git/commit.go
index 012ba975e8..705a97c927 100644
--- a/modules/git/commit.go
+++ b/modules/git/commit.go
@@ -437,6 +437,27 @@ func (c *Commit) GetBranchName() (string, error) {
 	return strings.SplitN(strings.TrimSpace(data), "~", 2)[0], nil
 }
 
+// GetAllBranches returns a slice with all branches that contains this commit
+func (c *Commit) GetAllBranches() ([]string, error) {
+	branchList := make([]string, 0)
+
+	cmd := NewCommand(c.repo.Ctx, "branch", "--format=%(refname:short)", "--contains").AddDynamicArguments(c.ID.String())
+	data, _, err := cmd.RunStdString(&RunOpts{Dir: c.repo.Path})
+	if err != nil {
+		return branchList, err
+	}
+
+	branchNames := strings.Split(strings.ReplaceAll(data, "\r\n", "\n"), "\n")
+	for _, branch := range branchNames {
+		branch = strings.TrimSpace(branch)
+		if branch != "" {
+			branchList = append(branchList, branch)
+		}
+	}
+
+	return branchList, nil
+}
+
 // CommitFileStatus represents status of files in a commit.
 type CommitFileStatus struct {
 	Added    []string
diff --git a/routers/api/v1/api.go b/routers/api/v1/api.go
index 58814d3b2e..0199ec8cbd 100644
--- a/routers/api/v1/api.go
+++ b/routers/api/v1/api.go
@@ -1341,6 +1341,9 @@ func Routes() *web.Route {
 					m.Post("", bind(api.UpdateRepoAvatarOption{}), repo.UpdateAvatar)
 					m.Delete("", repo.DeleteAvatar)
 				}, reqAdmin(), reqToken())
+				m.Group("/sync_fork", func() {
+					m.Post("/{branch}", repo.SyncForkBranch)
+				}, reqToken(), reqRepoWriter(unit.TypeCode))
 			}, repoAssignment())
 		}, tokenRequiresScopes(auth_model.AccessTokenScopeCategoryRepository))
 
diff --git a/routers/api/v1/repo/sync_fork.go b/routers/api/v1/repo/sync_fork.go
new file mode 100644
index 0000000000..fcc339db58
--- /dev/null
+++ b/routers/api/v1/repo/sync_fork.go
@@ -0,0 +1,54 @@
+package repo
+
+import (
+	"net/http"
+
+	"code.gitea.io/gitea/modules/context"
+	repo_service "code.gitea.io/gitea/services/repository"
+)
+
+// SyncForkBranch syncs a fork branch with the base branch
+func SyncForkBranch(ctx *context.APIContext) {
+	// swagger:operation POST /repos/{owner}/{repo}/sync_fork/{branch} repository repoSyncForkBranch
+	// ---
+	// summary: Syncs a fork
+	// produces:
+	// - application/json
+	// parameters:
+	// - name: owner
+	//   in: path
+	//   description: owner of the repo
+	//   type: string
+	//   required: true
+	// - name: repo
+	//   in: path
+	//   description: name of the repo
+	//   type: string
+	//   required: true
+	// - name: branch
+	//   in: path
+	//   description: The branch
+	//   type: string
+	//   required: true
+	// responses:
+	//   "400":
+	//     "$ref": "#/responses/error"
+	//   "204":
+	//     "$ref": "#/responses/empty"
+	//   "404":
+	//     "$ref": "#/responses/notFound"
+	if !ctx.Repo.Repository.IsFork {
+		ctx.Error(http.StatusBadRequest, "NoFork", "The Repo must be a fork")
+		return
+	}
+
+	branch := ctx.Params("branch")
+
+	err := repo_service.SyncFork(ctx, ctx.Doer, ctx.Repo.Repository, branch)
+	if err != nil {
+		ctx.Error(http.StatusInternalServerError, "DeleteReleaseByID", err)
+		return
+	}
+
+	ctx.Status(http.StatusNoContent)
+}
diff --git a/routers/web/repo/repo.go b/routers/web/repo/repo.go
index bede21be17..8ddcd5b86c 100644
--- a/routers/web/repo/repo.go
+++ b/routers/web/repo/repo.go
@@ -737,3 +737,15 @@ func PrepareBranchList(ctx *context.Context) {
 	}
 	ctx.Data["Branches"] = brs
 }
+
+func SyncFork(ctx *context.Context) {
+	branch := ctx.Params("branch")
+
+	err := repo_service.SyncFork(ctx, ctx.Doer, ctx.Repo.Repository, branch)
+	if err != nil {
+		ctx.ServerError("SyncFork", err)
+		return
+	}
+
+	ctx.Redirect(fmt.Sprintf("%s/src/branch/%s", ctx.Repo.RepoLink, util.PathEscapeSegments(ctx.Repo.BranchName)))
+}
diff --git a/routers/web/repo/view.go b/routers/web/repo/view.go
index e48865a2f5..d03d079998 100644
--- a/routers/web/repo/view.go
+++ b/routers/web/repo/view.go
@@ -50,6 +50,7 @@ import (
 	"code.gitea.io/gitea/routers/web/feed"
 	issue_service "code.gitea.io/gitea/services/issue"
 	files_service "code.gitea.io/gitea/services/repository/files"
+	repo_service "code.gitea.io/gitea/services/repository"
 
 	"github.com/nektos/act/pkg/model"
 
@@ -1107,6 +1108,26 @@ PostRecentBranchCheck:
 		}
 	}
 
+	if ctx.Repo.Repository.IsFork && ctx.Repo.IsViewBranch && len(ctx.Repo.TreePath) == 0 && ctx.Repo.CanWriteToBranch(ctx, ctx.Doer, ctx.Repo.BranchName) {
+		err = ctx.Repo.Repository.GetBaseRepo(ctx)
+		if err != nil {
+			ctx.ServerError("GetBaseRepo", err)
+			return
+		}
+
+		canSync, err := repo_service.CanSyncFork(ctx, ctx.Repo.Repository, ctx.Repo.BranchName)
+		if err != nil {
+			ctx.ServerError("CanSync", err)
+			return
+		}
+
+		if canSync {
+			ctx.Data["CanSyncFork"] = canSync
+			ctx.Data["SyncForkLink"] = fmt.Sprintf("%s/sync_fork/%s", ctx.Repo.RepoLink, util.PathEscapeSegments(ctx.Repo.BranchName))
+			ctx.Data["BaseBranchLink"] = fmt.Sprintf("%s/src/branch/%s", ctx.Repo.Repository.BaseRepo.HTMLURL(), util.PathEscapeSegments(ctx.Repo.BranchName))
+		}
+	}
+
 	ctx.Data["Paths"] = paths
 
 	branchLink := ctx.Repo.RepoLink + "/src/" + ctx.Repo.BranchNameSubURL()
diff --git a/routers/web/web.go b/routers/web/web.go
index caea7bdd1e..e59b716165 100644
--- a/routers/web/web.go
+++ b/routers/web/web.go
@@ -1558,6 +1558,8 @@ func registerRoutes(m *web.Route) {
 			m.Get("/forks", repo.Forks)
 		}, context.RepoRef(), reqRepoCodeReader)
 		m.Get("/commit/{sha:([a-f0-9]{4,64})}.{ext:patch|diff}", repo.MustBeNotEmpty, reqRepoCodeReader, repo.RawDiff)
+
+		m.Get("/sync_fork/{branch}", repo.MustBeNotEmpty, reqRepoCodeWriter, repo.SyncFork)
 	}, ignSignIn, context.RepoAssignment, context.UnitTypes())
 
 	m.Post("/{username}/{reponame}/lastcommit/*", ignSignInAndCsrf, context.RepoAssignment, context.UnitTypes(), context.RepoRefByType(context.RepoRefCommit), reqRepoCodeReader, repo.LastCommit)
diff --git a/services/repository/sync_fork.go b/services/repository/sync_fork.go
new file mode 100644
index 0000000000..8b8ae6aae3
--- /dev/null
+++ b/services/repository/sync_fork.go
@@ -0,0 +1,121 @@
+package repository
+
+import (
+	"context"
+	"fmt"
+	"slices"
+
+	git_model "code.gitea.io/gitea/models/git"
+	repo_model "code.gitea.io/gitea/models/repo"
+	user_model "code.gitea.io/gitea/models/user"
+	"code.gitea.io/gitea/modules/git"
+	repo_module "code.gitea.io/gitea/modules/repository"
+)
+
+// SyncFork syncs a branch of a fork with the base repo
+func SyncFork(ctx context.Context, doer *user_model.User, repo *repo_model.Repository, branch string) error {
+	err := repo.GetBaseRepo(ctx)
+	if err != nil {
+		return err
+	}
+
+	tmpPath, err := repo_module.CreateTemporaryPath("sync")
+	if err != nil {
+		return err
+	}
+	defer repo_module.RemoveTemporaryPath(tmpPath)
+
+	err = git.NewCommand(ctx, "clone", "-b").AddDynamicArguments(branch, repo.RepoPath(), tmpPath).Run(&git.RunOpts{Dir: tmpPath})
+	if err != nil {
+		return fmt.Errorf("Clone: %v", err)
+	}
+
+	gitRepo, err := git.OpenRepository(ctx, tmpPath)
+	if err != nil {
+		return err
+	}
+	defer gitRepo.Close()
+
+	command := git.NewCommand(gitRepo.Ctx, "remote", "add", "upstream")
+	command = command.AddDynamicArguments(repo.BaseRepo.RepoPath())
+	err = command.Run(&git.RunOpts{Dir: gitRepo.Path})
+	if err != nil {
+		return fmt.Errorf("RemoteAdd: %v", err)
+	}
+
+	err = git.NewCommand(gitRepo.Ctx, "fetch", "upstream").Run(&git.RunOpts{Dir: gitRepo.Path})
+	if err != nil {
+		return fmt.Errorf("FetchUpstream: %v", err)
+	}
+
+	command = git.NewCommand(gitRepo.Ctx, "checkout")
+	command = command.AddDynamicArguments(branch)
+	err = command.Run(&git.RunOpts{Dir: gitRepo.Path})
+	if err != nil {
+		return fmt.Errorf("Checkout: %v", err)
+	}
+
+	command = git.NewCommand(gitRepo.Ctx, "rebase")
+	command = command.AddDynamicArguments(fmt.Sprintf("upstream/%s", branch))
+	err = command.Run(&git.RunOpts{Dir: gitRepo.Path})
+	if err != nil {
+		return fmt.Errorf("Rebase: %v", err)
+	}
+
+	pushEnv := repo_module.PushingEnvironment(doer, repo)
+	err = git.NewCommand(ctx, "push", "origin").AddDynamicArguments(branch).Run(&git.RunOpts{Dir: tmpPath, Env: pushEnv})
+	if err != nil {
+		return fmt.Errorf("Push: %v", err)
+	}
+
+	return nil
+}
+
+// CanSyncFork returns if a branch of the fork can be synced with the base repo
+func CanSyncFork(ctx context.Context, repo *repo_model.Repository, branch string) (bool, error) {
+	forkBranch, err := git_model.GetBranch(ctx, repo.ID, branch)
+	if err != nil {
+		return false, err
+	}
+
+	baseBranch, err := git_model.GetBranch(ctx, repo.BaseRepo.ID, branch)
+	if err != nil {
+		if git_model.IsErrBranchNotExist(err) {
+			// If the base repo don't have the branch, we don't need to continue
+			return false, nil
+		}
+		return false, err
+	}
+
+	// If both branches has the same latest commit, we don't need to sync
+	if forkBranch.CommitID == baseBranch.CommitID {
+		return false, nil
+	}
+
+	// If the fork has newer commits, we can't sync
+	if forkBranch.CommitTime >= baseBranch.CommitTime {
+		return false, nil
+	}
+
+	// Check if the latest commit of the fork is also in the base
+	gitRepo, err := git.OpenRepository(ctx, repo.BaseRepo.RepoPath())
+	if err != nil {
+		return false, err
+	}
+	defer gitRepo.Close()
+
+	commit, err := gitRepo.GetCommit(forkBranch.CommitID)
+	if err != nil {
+		if git.IsErrNotExist(err) {
+			return false, nil
+		}
+		return false, err
+	}
+
+	branchList, err := commit.GetAllBranches()
+	if err != nil {
+		return false, err
+	}
+
+	return slices.Contains(branchList, branch), nil
+}
diff --git a/templates/repo/home.tmpl b/templates/repo/home.tmpl
index 5e27d9160c..73db9bc9c8 100644
--- a/templates/repo/home.tmpl
+++ b/templates/repo/home.tmpl
@@ -178,6 +178,18 @@
 				{{end}}
 			</div>
 		</div>
+
+		{{if .CanSyncFork}}
+			<div class="ui positive message gt-df gt-ac">
+				<div class="gt-f1">
+					This branch is behind <a href="{{.BaseBranchLink}}">{{printf "%s/%s:%s" .Repository.BaseRepo.OwnerName .Repository.BaseRepo.Name .BranchName}}</a>
+				</div>
+				<a role="button" class="ui compact positive button gt-m-0" href="{{.SyncForkLink}}">
+					Sync
+				</a>
+			</div>
+		{{end}}
+
 		{{if .IsViewFile}}
 			{{template "repo/view_file" .}}
 		{{else if .IsBlame}}
diff --git a/templates/swagger/v1_json.tmpl b/templates/swagger/v1_json.tmpl
index 8a40cf76d4..4253e5348f 100644
--- a/templates/swagger/v1_json.tmpl
+++ b/templates/swagger/v1_json.tmpl
@@ -13388,6 +13388,52 @@
         }
       }
     },
+    "/repos/{owner}/{repo}/sync_fork/{branch}": {
+      "post": {
+        "produces": [
+          "application/json"
+        ],
+        "tags": [
+          "repository"
+        ],
+        "summary": "Syncs a fork",
+        "operationId": "repoSyncForkBranch",
+        "parameters": [
+          {
+            "type": "string",
+            "description": "owner of the repo",
+            "name": "owner",
+            "in": "path",
+            "required": true
+          },
+          {
+            "type": "string",
+            "description": "name of the repo",
+            "name": "repo",
+            "in": "path",
+            "required": true
+          },
+          {
+            "type": "string",
+            "description": "The branch",
+            "name": "branch",
+            "in": "path",
+            "required": true
+          }
+        ],
+        "responses": {
+          "204": {
+            "$ref": "#/responses/empty"
+          },
+          "400": {
+            "$ref": "#/responses/error"
+          },
+          "404": {
+            "$ref": "#/responses/notFound"
+          }
+        }
+      }
+    },
     "/repos/{owner}/{repo}/tags": {
       "get": {
         "produces": [