@@ -24,8 +24,8 @@ git branch (-m|-M) [<old-branch>] <new-branch>
 git branch (-c|-C) [<old-branch>] <new-branch>
 git branch (-d|-D) [-r] <branch-name>...
 git branch --edit-description [<branch-name>]
-git branch --forked <remote>...
-git branch [-f] --prune-merged <remote>...
+git branch --forked (<remote>... | --all-remotes)
+git branch [-f] --prune-merged (<remote>... | --all-remotes)
 
 DESCRIPTION
 -----------

@@ -226,6 +226,11 @@ delete them regardless. The currently checked-out branch in any
 worktree is always preserved, as is any branch with
 `branch.<name>.pruneMerged` set to `false`.
 
+`--all-remotes`::
+	With `--forked` or `--prune-merged`, act on every
+	configured remote in addition to any explicit _<remote>_
+	arguments.
+
 `-v`::
 `-vv`::
 `--verbose`::

@@ -703,6 +703,13 @@ static void copy_or_rename_branch(const char *oldname, const char *newname, int
 	free_worktrees(worktrees);
 }
 
+static int collect_remote_name(struct remote *remote, void *cb_data)
+{
+	struct string_list *remote_names = cb_data;
+	string_list_insert(remote_names, remote->name);
+	return 0;
+}
+
 static void parse_forked_args(int argc, const char **argv,
 			      struct string_list *remote_names,
 			      struct string_list *tracking_refs)

@@ -792,7 +799,7 @@ static void collect_default_branch_refs(const struct string_list *remote_names,
 	}
 }
 
-static void collect_forked_set(int argc, const char **argv,
+static void collect_forked_set(int argc, const char **argv, int all_remotes,
 			       struct string_list *protected_default_refs,
 			       struct string_list *out)
 {

@@ -805,6 +812,8 @@ static void collect_forked_set(int argc, const char **argv,
 	};
 
 	parse_forked_args(argc, argv, &remote_names, &tracking_refs);
+	if (all_remotes)
+		for_each_remote(collect_remote_name, &remote_names);
 
 	refs_for_each_branch_ref(get_main_ref_store(the_repository),
 				 collect_forked_branch, &cb);

@@ -818,15 +827,15 @@ static void collect_forked_set(int argc, const char **argv,
 	string_list_clear(&tracking_refs, 0);
 }
 
-static int list_forked_branches(int argc, const char **argv)
+static int list_forked_branches(int argc, const char **argv, int all_remotes)
 {
 	struct string_list out = STRING_LIST_INIT_DUP;
 	struct string_list_item *item;
 
-	if (!argc)
-		die(_("--forked requires at least one <remote>"));
+	if (!argc && !all_remotes)
+		die(_("--forked requires at least one <remote> or --all-remotes"));
 
-	collect_forked_set(argc, argv, NULL, &out);
+	collect_forked_set(argc, argv, all_remotes, NULL, &out);
 	for_each_string_list_item(item, &out)
 		puts(item->string);
 

@@ -849,8 +858,8 @@ static struct commit *resolve_remote_head(const char *remote_name)
 	return commit;
 }
 
-static int prune_merged_branches(int argc, const char **argv, int force,
-				 int quiet)
+static int prune_merged_branches(int argc, const char **argv,
+				 int all_remotes, int force, int quiet)
 {
 	struct string_list candidates = STRING_LIST_INIT_DUP;
 	struct string_list protected_default_refs = STRING_LIST_INIT_DUP;

@@ -861,10 +870,11 @@ static int prune_merged_branches(int argc, const char **argv, int force,
 	int n_not_merged = 0;
 	int ret = 0;
 
-	if (!argc)
-		die(_("--prune-merged requires at least one <remote>"));
+	if (!argc && !all_remotes)
+		die(_("--prune-merged requires at least one <remote> or --all-remotes"));
 
-	collect_forked_set(argc, argv, &protected_default_refs, &candidates);
+	collect_forked_set(argc, argv, all_remotes, &protected_default_refs,
+			   &candidates);
 
 	for_each_string_list_item(item, &candidates) {
 		const char *short_name = item->string;

@@ -1001,6 +1011,7 @@ int cmd_branch(int argc,
 	    unset_upstream = 0, show_current = 0, edit_description = 0;
 	int forked = 0;
 	int prune_merged = 0;
+	int all_remotes = 0;
 	const char *new_upstream = NULL;
 	int noncreate_actions = 0;
 	/* possible options */

@@ -1058,6 +1069,9 @@ int cmd_branch(int argc,
 			N_("list local branches forked from the given <remote>s")),
 		OPT_BOOL(0, "prune-merged", &prune_merged,
 			N_("delete local branches forked from the given <remote>s that are merged into their upstream")),
+		OPT_BOOL_F(0, "all-remotes", &all_remotes,
+			N_("with --forked or --prune-merged, act on every configured remote"),
+			PARSE_OPT_NONEG),
 		OPT__FORCE(&force, N_("force creation, move/rename, deletion"), PARSE_OPT_NOCOMPLETE),
 		OPT_MERGED(&filter, N_("print only branches that are merged")),
 		OPT_NO_MERGED(&filter, N_("print only branches that are not merged")),

@@ -1101,6 +1115,9 @@ int cmd_branch(int argc,
 	argc = parse_options(argc, argv, prefix, options, builtin_branch_usage,
 			     0);
 
+	if (all_remotes && !forked && !prune_merged)
+		die(_("--all-remotes requires --forked or --prune-merged"));
+
 	if (!delete && !rename && !copy && !edit_description && !new_upstream &&
 	    !show_current && !unset_upstream && !forked && !prune_merged &&
 	    argc == 0)

@@ -1154,10 +1171,10 @@ int cmd_branch(int argc,
 				      quiet, 0, NULL);
 		goto out;
 	} else if (forked) {
-		ret = list_forked_branches(argc, argv);
+		ret = list_forked_branches(argc, argv, all_remotes);
 		goto out;
 	} else if (prune_merged) {
-		ret = prune_merged_branches(argc, argv, force, quiet);
+		ret = prune_merged_branches(argc, argv, all_remotes, force, quiet);
 		goto out;
 	} else if (show_current) {
 		print_current_branch_name();

@@ -1771,6 +1771,27 @@ test_expect_success '--forked requires at least one <remote>' '
 	test_grep "at least one <remote>" err
 '
 
+test_expect_success '--forked --all-remotes covers every configured remote' '
+	git -C forked branch --forked --all-remotes >actual &&
+	cat >expect <<-\EOF &&
+	local-foreign
+	local-one
+	local-two
+	main
+	EOF
+	test_cmp expect actual
+'
+
+test_expect_success '--forked --all-remotes still validates explicit <remote>' '
+	test_must_fail git -C forked branch --forked nope --all-remotes 2>err &&
+	test_grep "neither a configured remote nor a remote-tracking branch" err
+'
+
+test_expect_success '--all-remotes alone is rejected' '
+	test_must_fail git -C forked branch --all-remotes 2>err &&
+	test_grep "requires --forked or --prune-merged" err
+'
+
 test_expect_success '--prune-merged: setup' '
 	test_create_repo pm-upstream &&
 	test_commit -C pm-upstream base &&

@@ -1955,4 +1976,23 @@ test_expect_success 'branch -d still deletes a pruneMerged=false branch' '
 	test_must_fail git -C pm-optout-d rev-parse --verify refs/heads/one
 '
 
+test_expect_success '--prune-merged --all-remotes covers every configured remote' '
+	test_when_finished "rm -rf pm-allremotes" &&
+	git clone pm-upstream pm-allremotes &&
+	test_create_repo pm-other &&
+	test_commit -C pm-other other-base &&
+	git -C pm-other branch foreign other-base &&
+	git -C pm-allremotes remote add other ../pm-other &&
+	git -C pm-allremotes fetch other &&
+	git -C pm-allremotes branch one --track origin/one &&
+	git -C pm-allremotes branch foreign --track other/foreign &&
+
+	git -C pm-allremotes update-ref -d refs/remotes/origin/one &&
+	git -C pm-allremotes update-ref -d refs/remotes/other/foreign &&
+	git -C pm-allremotes branch --force --prune-merged --all-remotes &&
+
+	test_must_fail git -C pm-allremotes rev-parse --verify refs/heads/one &&
+	test_must_fail git -C pm-allremotes rev-parse --verify refs/heads/foreign
+'
+
 test_done