diff --git a/cli/tests/integration/fmt_tests.rs b/cli/tests/integration/fmt_tests.rs
index aa807b7278..28a1dda7d5 100644
--- a/cli/tests/integration/fmt_tests.rs
+++ b/cli/tests/integration/fmt_tests.rs
@@ -125,6 +125,39 @@ fn fmt_ignore_unexplicit_files() {
   );
 }
 
+#[test]
+fn fmt_auto_ignore_git() {
+  use std::fs::{create_dir_all, File};
+  use std::io::Write;
+  use std::path::PathBuf;
+  fn create_bad_json(t: PathBuf) {
+    let bad_json_path = t.join("bad.json");
+    let mut bad_json_file = File::create(bad_json_path).unwrap();
+    writeln!(bad_json_file, "bad json").unwrap();
+  }
+  let t = TempDir::new().unwrap().path().join("target");
+  let nest_git = t.join("nest").join(".git");
+  let git_dir = t.join(".git");
+  create_dir_all(&nest_git).unwrap();
+  create_dir_all(&git_dir).unwrap();
+  create_bad_json(nest_git);
+  create_bad_json(git_dir);
+  let output = util::deno_cmd()
+    .current_dir(t)
+    .env("NO_COLOR", "1")
+    .arg("fmt")
+    .stderr(std::process::Stdio::piped())
+    .spawn()
+    .unwrap()
+    .wait_with_output()
+    .unwrap();
+  assert!(!output.status.success());
+  assert_eq!(
+    String::from_utf8_lossy(&output.stderr),
+    "error: No target files found.\n"
+  );
+}
+
 itest!(fmt_quiet_check_fmt_dir {
   args: "fmt --check --quiet fmt/regular/",
   output_str: Some(""),
diff --git a/cli/tools/fmt.rs b/cli/tools/fmt.rs
index 3c5ab523e4..401fe836e2 100644
--- a/cli/tools/fmt.rs
+++ b/cli/tools/fmt.rs
@@ -90,31 +90,32 @@ pub async fn format(
     maybe_fmt_config.map(|c| c.options).unwrap_or_default(),
   );
 
+  let fmt_predicate =
+    |path: &Path| is_supported_ext_fmt(path) && !is_contain_git(path);
+
   let resolver = |changed: Option<Vec<PathBuf>>| {
     let files_changed = changed.is_some();
 
-    let result =
-      collect_files(&include_files, &exclude_files, is_supported_ext_fmt).map(
-        |files| {
-          let refmt_files = if let Some(paths) = changed {
-            if check {
-              files
-                .iter()
-                .any(|path| paths.contains(path))
-                .then(|| files)
-                .unwrap_or_else(|| [].to_vec())
-            } else {
-              files
-                .into_iter()
-                .filter(|path| paths.contains(path))
-                .collect::<Vec<_>>()
-            }
+    let result = collect_files(&include_files, &exclude_files, fmt_predicate)
+      .map(|files| {
+        let refmt_files = if let Some(paths) = changed {
+          if check {
+            files
+              .iter()
+              .any(|path| paths.contains(path))
+              .then(|| files)
+              .unwrap_or_else(|| [].to_vec())
           } else {
             files
-          };
-          (refmt_files, fmt_options.clone())
-        },
-      );
+              .into_iter()
+              .filter(|path| paths.contains(path))
+              .collect::<Vec<_>>()
+          }
+        } else {
+          files
+        };
+        (refmt_files, fmt_options.clone())
+      });
 
     let paths_to_watch = include_files.clone();
     async move {
@@ -150,15 +151,14 @@ pub async fn format(
     )
     .await?;
   } else {
-    let files =
-      collect_files(&include_files, &exclude_files, is_supported_ext_fmt)
-        .and_then(|files| {
-          if files.is_empty() {
-            Err(generic_error("No target files found."))
-          } else {
-            Ok(files)
-          }
-        })?;
+    let files = collect_files(&include_files, &exclude_files, fmt_predicate)
+      .and_then(|files| {
+        if files.is_empty() {
+          Err(generic_error("No target files found."))
+        } else {
+          Ok(files)
+        }
+      })?;
     operation((files, fmt_options.clone())).await?;
   }
 
@@ -624,6 +624,10 @@ fn is_supported_ext_fmt(path: &Path) -> bool {
   }
 }
 
+fn is_contain_git(path: &Path) -> bool {
+  path.components().any(|c| c.as_os_str() == ".git")
+}
+
 #[test]
 fn test_is_supported_ext_fmt() {
   assert!(!is_supported_ext_fmt(Path::new("tests/subdir/redirects")));
@@ -650,3 +654,11 @@ fn test_is_supported_ext_fmt() {
   assert!(is_supported_ext_fmt(Path::new("foo.json")));
   assert!(is_supported_ext_fmt(Path::new("foo.JsON")));
 }
+
+#[test]
+fn test_is_located_in_git() {
+  assert!(is_contain_git(Path::new("test/.git")));
+  assert!(is_contain_git(Path::new(".git/bad.json")));
+  assert!(is_contain_git(Path::new("test/.git/bad.json")));
+  assert!(!is_contain_git(Path::new("test/bad.git/bad.json")));
+}