diff --git a/cpp/src/arrow/filesystem/test_util.cc b/cpp/src/arrow/filesystem/test_util.cc
index da73a8ec16b5..1b96e485fdf9 100644
--- a/cpp/src/arrow/filesystem/test_util.cc
+++ b/cpp/src/arrow/filesystem/test_util.cc
@@ -811,6 +811,11 @@ void GenericFileSystemTest::TestGetFileInfoSelector(FileSystem* fs) {
   ASSERT_OK_AND_ASSIGN(info, fs->GetFileInfo("AB"));
   AssertFileInfo(info, "AB", FileType::Directory, first_dir_time);
   ASSERT_OK_AND_ASSIGN(info, fs->GetFileInfo("AB/CD/ghi"));
+  // aws-sdk-cpp >= 1.11.900 keeps ms in S3 listings, but HeadObject only has seconds
+  if (info.mtime() == std::chrono::floor<std::chrono::seconds>(info.mtime()) &&
+      first_file_time == std::chrono::floor<std::chrono::milliseconds>(first_file_time)) {
+    first_file_time = std::chrono::floor<std::chrono::seconds>(first_file_time);
+  }
   AssertFileInfo(info, "AB/CD/ghi", FileType::File, first_file_time, 15);
 
   // Doesn't exist