U42

U42 or U-42 may refer to:


 * GERMAN SUBMARINE U-42, various vessels
 * Great ditrigonal dodecicosidodecahedron
 * HMS Modeste (U42), a sloop of the Royal Navy
 * Small nucleolar RNA SNORD42
 * South Valley Regional Airport, serving Salt Lake City, Utah, United States
 * U42, a line of the Dortmund Stadtbahn