U50
U50 may refer to:

Naval vessels 
 , various vessels
 , a sloop of the Royal Navy
 U-50-class submarine of the Austro-Hungarian Navy

Other uses 
 GE U50, a diesel-electric locomotive
 Small dodecicosahedron
 Small nucleolar RNA SNORD50
 U50 statistic, in computational biology
 Uppland Runic Inscription 50