Admiral Sir Douglas Romilly Lothian Nicholson, KCMG, KCVO (4 March 1867 – 8 February 1946) was a senior Royal Navy officer who commanded the Reserve Fleet.

[1] He was appointed in command of the destroyer HMS Spiteful on 11 January 1901,[2] as she was serving in home waters, and was in charge when she ran aground near the Isle of Wight the following month and during a collision with sister ship HMS Peterel in October.

After a year with the Spiteful, he was appointed in command of HMS Dove on 24 February 1902,[3] serving in the Channel Fleet as part of the Portsmouth instructional flotilla.

[5] Douglas and the crew transferred to the recently completed torpedo boat destroyer HMS Success, which was commissioned at Portsmouth on 9 June.

[1] He served in World War I as commanding officer of HMS Agincourt in the Grand Fleet from 1914.