U-98 may refer to one of the following German submarines:
- SM U-98, a Type U 93 submarine launched in 1917 and that served in the First World War until surrendered on 16 January 1919; broken up at Blyth in 1922
- During the First World War, Germany also had these submarines with similar names:
- SM UB-98, a Type UB III submarine launched in 1918 and surrendered on 21 November 1918; broken up at Parmadoc in 1922
- SM UC-98, a Type UC III submarine launched in 1918 and surrendered on 24 November 1918; broken up at La Spezia in April 1919
- During the First World War, Germany also had these submarines with similar names:
- German submarine U-98 (1940), a Type VIIC submarine that served in the Second World War until sunk on 15 November 1942
This article includes a list of ships with the same or similar names. If an internal link for a specific ship led you here, you may wish to change the link to point directly to the intended ship article, if one exists.