diff --git a/cpp/src/arrow/filesystem/s3fs.cc b/cpp/src/arrow/filesystem/s3fs.cc
index 20db3486cd247..f011dcf5d9355 100644
--- a/cpp/src/arrow/filesystem/s3fs.cc
+++ b/cpp/src/arrow/filesystem/s3fs.cc
@@ -2410,9 +2410,10 @@ class S3FileSystem::Impl : public std::enable_shared_from_this<S3FileSystem::Imp
                     DCHECK_GT(file_info.path().size(), bucket.size());
                     auto file_path = file_info.path().substr(bucket.size() + 1);
                     if (file_info.IsDirectory()) {
+                      DCHECK(internal::AssertNoTrailingSlash(file_path));
                       file_path = file_path + kSep;
                     }
-                    file_paths.push_back(file_path);
+                    file_paths.push_back(std::move(file_path));
                   }
                   scheduler->AddSimpleTask(
                       [=, file_paths = std::move(file_paths)] {