U47
U47 may refer to:

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

Other uses 
 Great ditrigonal icosidodecahedron
 Neumann U 47, a microphone
 Small nucleolar RNA SNORD47
 U 47 – Kapitänleutnant Prien, a German war film
 Uppland Runic Inscription 47
 U47, a line of the Dortmund Stadtbahn