USS is a TLA that may stand for:
- United States Ship Typically as a ship prefix in the United States Navy
- Uncorrected sum of squares
- Under-seat steering
- Uniform Symbology Specification
- Union syndicale suisse (uss.ch)
- United Star Ship (Star Trek)
- United States Senate
- United States Steel Corporation
- Universities Superannuation Scheme (UK)
- Unix System Services
- Unix Systems Services
- USA Swimming
- User Support Services (several)