SM U-26

SM U-26 was one of the 329 submarines serving in the Imperial German Navy (Kaiserliche Marine) in World War I.

U-26 was engaged in the Naval warfare of World War I in the Baltic Sea. On October 11, 1914, she sank the Russian cruiser Pallada (1906), inflicting the first loss of the war on the Russian navy.

The boat did not return from sea in August 1915 and is assumed to have struck a mine off the coast of Finland, being lost with its entire crew of 30.