HMS P611 was a submarine of the Oruç Reis class originally built for the Turkish Navy intended to be named Oruç Reis, but commissioned into the Royal Navy after the outbreak of war.

She was a modified British S class design launched on 19 July 1940 by Vickers Armstrong at Barrow.

Due to the pressing need for her, she was commissioned into the Royal Navy on 1 December 1941 so she could be sent to Turkey.

She arrived at the Turkish naval base at İskenderun on 9 May 1942 and was handed over to the Turkish Navy as Oruç Reis.

This article about a specific naval submarine of the United Kingdom is a stub.