diff --git a/docs/templates.md b/docs/templates.md
index 05a6eee474..4238fd2a57 100644
--- a/docs/templates.md
+++ b/docs/templates.md
@@ -56,6 +56,8 @@ The following operators are supported.
 
 The following functions are defined.
 
+* `fill(width: Integer, content: Template) -> Template`: Fill lines at
+  the given `width`.
 * `indent(prefix: Template, content: Template) -> Template`: Indent
   non-empty lines by the given `prefix`.
 * `label(label: Template, content: Template) -> Template`: Apply label to
diff --git a/src/template_parser.rs b/src/template_parser.rs
index 55dc4780e0..132573ee26 100644
--- a/src/template_parser.rs
+++ b/src/template_parser.rs
@@ -1071,6 +1071,16 @@ fn build_global_function<'a, L: TemplateLanguage<'a>>(
     function: &FunctionCallNode,
 ) -> TemplateParseResult<Expression<L::Property>> {
     let property = match function.name {
+        "fill" => {
+            let [width_node, content_node] = expect_exact_arguments(function)?;
+            let width = expect_integer_expression(language, width_node)?;
+            let content = build_expression(language, content_node)?.into_template();
+            let template = ReformatTemplate::new(content, move |context, formatter, recorded| {
+                let width = width.extract(context).try_into().unwrap_or(0);
+                text_util::write_wrapped(formatter, recorded, width)
+            });
+            language.wrap_template(template)
+        }
         "indent" => {
             let [prefix_node, content_node] = expect_exact_arguments(function)?;
             let prefix = build_expression(language, prefix_node)?.into_template();
diff --git a/tests/test_templater.rs b/tests/test_templater.rs
index 7f88c69714..c3c6ebbadb 100644
--- a/tests/test_templater.rs
+++ b/tests/test_templater.rs
@@ -332,6 +332,45 @@ fn test_templater_signature() {
     insta::assert_snapshot!(render(r#"author.username()"#), @"x");
 }
 
+#[test]
+fn test_templater_fill_function() {
+    let test_env = TestEnvironment::default();
+    test_env.jj_cmd_success(test_env.env_root(), &["init", "repo", "--git"]);
+    let repo_path = test_env.env_root().join("repo");
+    let render = |template| get_colored_template_output(&test_env, &repo_path, "@-", template);
+
+    insta::assert_snapshot!(
+        render(r#"fill(20, "The quick fox jumps over the " ++
+                       label("error", "lazy") ++ " dog\n")"#),
+        @r###"
+    The quick fox jumps
+    over the lazy dog
+    "###);
+
+    // Word-wrap, then indent
+    insta::assert_snapshot!(
+        render(r#""START marker to help insta\n" ++
+                  indent("    ", fill(20, "The quick fox jumps over the " ++
+                                      label("error", "lazy") ++ " dog\n"))"#),
+        @r###"
+    START marker to help insta
+        The quick fox jumps
+        over the lazy dog
+    "###);
+
+    // Word-wrap indented (no special handling for leading spaces)
+    insta::assert_snapshot!(
+        render(r#""START marker to help insta\n" ++
+                  fill(20, indent("    ", "The quick fox jumps over the " ++
+                                  label("error", "lazy") ++ " dog\n"))"#),
+        @r###"
+    START marker to help insta
+        The quick fox
+    jumps over the lazy
+    dog
+    "###);
+}
+
 #[test]
 fn test_templater_indent_function() {
     let test_env = TestEnvironment::default();