SM U-111 was one of the 329 submarines serving in the Imperial German Navy in World War I. She took part in the First Battle of the Atlantic. Completed at Kiel early in January 1918, she went to the Kiel School for shakedown and training until March, when she joined . She was monitored continuously by British Naval Intelligence (Room 40), on which her movement reports are based. All her operations took place in 1918.