- YOS stands for Yosemite (Amtrak station code; Yosemite, CA)
- YOS stands for Years Of Service
- YOS stands for Oil Storage Barge (Non Self-Propelled)
- YOS stands for Your Operating System
- YOS stands for Your Obedient Servant (closing salutation chiefly 18th century British)
- YOS stands for Yahoo Online Status (Yahoo Messenger)
- YOS stands for District Barge, Oil Storage (US Navy)
- YOS stands for Yttrium Ortho-Silicate
YOS