Transactional NTFS (abbreviated TxF) is a component introduced in Windows Vista and present in later versions of the Microsoft Windows operating system that brings the concept of atomic transactions to the NTFS file system, allowing Windows application developers to write file-output routines that are guaranteed to either succeed completely or to fail completely. Major operating system components, including System Restore, Task Scheduler, and Windows Update, rely on TxF for stability. During the development of Windows Vista, WinFS also relied on TxF for storing files.

Due to its complexity and various nuances which developers need to consider as part of application development, Microsoft has deprecated TxF and stated that it may be removed in a future version of Windows. Microsoft has strongly recommended that developers investigate using the alternatives rather than adopting the Transactional NTFS API platform which may not be available in future versions of Windows.