- UAT (User Acceptance Testing)
- UATA (Ultra-Advanced Technology Attachment)
- UATB (University Alumni Travel Benefits)
- UATBP (University Alumni Travel Benefits Program)
- UATC (Unilateral Apprenticeship and Training Committee)
- UATD (Unit Adventurous Training Directive)
- UATD-CV (Unidad de Apoyo Tecnico a la Docencia at Campus Virtual)
- UATN (Urban America Television Network)
- UATT (University Associates Training Technology)
- UAU (Unix for Advanced Users)
- UAV (Unmanned aerial vehicle)
- UAV-C (Unmanned Aerial Vehicle - Close Range)
- UAV-C GSC (Unmanned Aerial Vehicle - Close Range - Ground Control Station)
- UAV-CR (Unmanned Aerial Vehicle - Close Range)
- UAV-E (Unmanned Aerial Vehicle - Endurance)
- UAV-GCS (Unmanned Aerial Vehicle - Ground Control Station)
- UAV-MPCS (Unmanned Aerial Vehicle - Mission Planning and Control Station)
- UAV-MR (Unmanned Aerial Vehicle - Medium Range)
- UAV-SR (Unmanned Aerial Vehicle - Short Range)
- UAW (United Academic Workers)
- UAX (UHF (Ultra-High Frequency) Array Experimental)
- UAX-1 (Unicode Standard AnneX 1, Burmese, Khmer, Ethiopian ( Superceded by Unicode Standard Version 3.0))
- UAX-10 (Unicode Standard AnneX 10, Unicode Collation Algorithm)
- UAX-11 (Unicode Standard AnneX 11, East Asian Width)
- UAX-13 (Unicode Standard AnneX 13, Unicode Newline Guidlines - Superceded by Unicode Standard Version 4.0)
- UAX-14 (Unicode Standard AnneX 14, Line Breaking Properties)
- UAX-15 (Unicode Standard AnneX 15, Unicode Normalization Forms)
- UAX-16 (Unicode Standard AnneX 16, UTF- EBCDIC)
- UAX-17 (Unicode Standard AnneX 17, Character Encoding Model)
- UAX-18 (Unicode Standard AnneX 18, Unicode Regular Expression Guidelines)