Peter Muir Doig (27 October 1911 – 31 October 1996) was a British Labour Party politician.
Doig was educated at Blackness School, Dundee before taking evening classes.
He later became a sales supervisor.
He joined the Labour Party in 1930.
During the Second World War he served in the Royal Air Force.
He was elected a Dundee town councillor for ten years, serving as honorary town treasurer.
Doig contested Aberdeen South in 1959.
He was Member of Parliament for Dundee West from a 1963 by-election to 1979, preceding Ernie Ross.
On 22 September 1963, Doig was chosen ahead of five other people to be the Labour Party candidate in the by-election.
At the time he was a bakery supervisor and chairman of the Labour group on Dundee Town Council.
He was also deputy chairman of the council.In 1966 Doig was recorded as a member of the Transport and General Workers Union and the Co-operative Society.
He was married with two sons.In the 1970s Doig was one of a small number of Labour MPs who supported the restoration of capital punishment, and was reported to favour a "hard line" approach towards crime.
In 1979, when chairing the Scottish Standing Committee of MPs he used his casting vote to support a Conservative proposal to give police in Scotland wider powers to search for offensive weapons.