HMS Forfar (F30) was a British ocean liner that was commissioned into the Royal Navy as an armed merchant cruiser in 1939 and sunk by enemy action in 1940.

She was launched in Scotland in 1920 as a transatlantic liner for the Canadian Pacific Steamship Company as Montrose.

Canadian Pacific ordered a set of three ships from shipyards on the River Clyde.

[1][2] The Fairfield Shipbuilding and Engineering Company in Govan built Montrose as yard number 529.

Lady Raeburn, wife of the Director-General of the UK Ministry of Shipping, launched Montrose on 14 December 1920.

She had twin screws, each driven by high- and low-pressure steam turbines via single reduction gearing.

[8][9] On 31 July 1928 Montrose collided with the British cargo ship Rose Castle in the Saint Lawrence River, Quebec, Canada.