diff --git a/samcli/lib/utils/definition_validator.py b/samcli/lib/utils/definition_validator.py
index bab018a632..2a92daf47d 100644
--- a/samcli/lib/utils/definition_validator.py
+++ b/samcli/lib/utils/definition_validator.py
@@ -1,6 +1,7 @@
 """DefinitionValidator for Validating YAML and JSON Files"""
 
 import logging
+import time
 from pathlib import Path
 from typing import Any, Dict, Optional
 
@@ -11,6 +12,9 @@
 
 LOG = logging.getLogger(__name__)
 
+FILE_READ_ATTEMPTS = 3
+FILE_READ_RETRY_DELAY = 0.1
+
 
 class DefinitionValidator:
     _path: Path
@@ -75,7 +79,7 @@ def validate_file(self) -> bool:
             return False
 
         try:
-            self._data = parse_yaml_file(str(self._path))
+            self._data = self._parse_file()
         except (ValueError, yaml.YAMLError) as e:
             LOG.debug(
                 "File %s failed to validate due to it file cannot be parsed. \
@@ -84,4 +88,32 @@ def validate_file(self) -> bool:
                 exc_info=e,
             )
             return False
+        except OSError as e:
+            LOG.warning(
+                "File %s failed to validate because it cannot be read. \
+The change will not be synced until the file is saved again.",
+                self._path,
+                exc_info=e,
+            )
+            return False
         return True
+
+    def _parse_file(self) -> Dict[str, Any]:
+        """Read and parse the definition file, retrying while it is locked by another process.
+
+        Returns
+        -------
+        Dict[str, Any]
+            Parsed content of the definition file.
+        """
+        remaining_attempts = FILE_READ_ATTEMPTS
+        delay = FILE_READ_RETRY_DELAY
+        while True:
+            try:
+                return parse_yaml_file(str(self._path))
+            except PermissionError:
+                remaining_attempts -= 1
+                if not remaining_attempts:
+                    raise
+                time.sleep(delay)
+                delay *= 2
diff --git a/tests/unit/lib/utils/test_definition_validator.py b/tests/unit/lib/utils/test_definition_validator.py
index bbb16e1a4f..4a203ec8c8 100644
--- a/tests/unit/lib/utils/test_definition_validator.py
+++ b/tests/unit/lib/utils/test_definition_validator.py
@@ -69,3 +69,29 @@ def test_detect_change_for_file_opened_event(self, parse_yaml_file_mock):
         validator = DefinitionValidator(self.path, detect_change=True, initialize_data=True)
         event = FileOpenedEvent("src_path")
         self.assertFalse(validator.validate_change(event))
+
+    @patch("samcli.lib.utils.definition_validator.time.sleep")
+    @patch("samcli.lib.utils.definition_validator.parse_yaml_file")
+    def test_detect_change_retries_locked_file(self, parse_yaml_file_mock, sleep_mock):
+        parse_yaml_file_mock.side_effect = [{"A": 1}, PermissionError(13, "Permission denied"), {"B": 1}]
+
+        validator = DefinitionValidator(self.path, detect_change=True, initialize_data=True)
+        self.assertTrue(validator.validate_change())
+
+    @patch("samcli.lib.utils.definition_validator.time.sleep")
+    @patch("samcli.lib.utils.definition_validator.parse_yaml_file")
+    def test_detect_change_locked_file(self, parse_yaml_file_mock, sleep_mock):
+        parse_yaml_file_mock.side_effect = PermissionError(13, "Permission denied")
+
+        validator = DefinitionValidator(self.path, detect_change=True, initialize_data=False)
+        self.assertFalse(validator.validate_change())
+        self.assertEqual(parse_yaml_file_mock.call_count, 3)
+
+    @patch("samcli.lib.utils.definition_validator.time.sleep")
+    @patch("samcli.lib.utils.definition_validator.parse_yaml_file")
+    def test_detect_change_unreadable_file(self, parse_yaml_file_mock, sleep_mock):
+        parse_yaml_file_mock.side_effect = IsADirectoryError(21, "Is a directory")
+
+        validator = DefinitionValidator(self.path, detect_change=True, initialize_data=False)
+        self.assertFalse(validator.validate_change())
+        self.assertEqual(parse_yaml_file_mock.call_count, 1)