U-16 may refer to one of the following German submarines:
, was a unique submarine; launched in 1911 and served in the First World War until sunk in an accident on 8 February 1919, en route to surrender During the First World War, Germany also had these submarines with similar names: , a Type UB I submarine launched in 1915 and sunk 10 May 1918 , a Type UC II submarine launched in 1916 and lost in October 1917 , a Type IIB submarine that served in the Second World War and was sunk on 25 October 1939 , a Type 206 submarine of the Bundesmarine that was launched in 1973 and was sold to Columbia after decommissioning in 2011 for spare parts.