Maureen Morfydd Colquhoun (/kəˈhuːn/ kə-HOON; née Smith, 12 August 1928 – 2 February 2021) was a British economist and Labour politician. She was Britain's first openly lesbian member of Parliament (MP).

Smith was born in Eastbourne, Sussex, on 12 August 1928, where she was raised by her Irish mother, Elizabeth Smith, a single parent, in a politically active home. She was educated at a local convent school, a commercial college in Brighton, then at the London School of Economics and later worked as a literary research assistant.^{[dead link]} She joined the Labour Party in her late teens and worked as a civil servant, a literary research assistant and in an art gallery in Shoreham, West Sussex, before entering politics.

Colquhoun contested Tonbridge at the 1970 general election. She served as a councillor in Shoreham-by-Sea, from 1965 to 1974. The only female Shoreham councillor at the time, she was blocked by Conservative opponents from sitting on any of the authority's committees. In January 1970, a decision by Shoreham Urban District Council to block her from appointments as a primary school manager, school governor and library committee membership, on the grounds that she talked too much, was overruled.

Colquhoun was elected as the Member of Parliament (MP) for Northampton North at the February 1974 general election, and identified with the Tribune Group, and served as the group's treasurer. Arguing in favour of creche facilities for female delegates at the following year's Labour conference, she said in October 1975: "It is outrageous that we have to ask for this. The Labour Party pays mere lip service to International Women's Day. ... Young women are deterred from coming because there is no provision for their babies. Those who do are not even allowed to bring their toddlers into the gallery."

Colquhoun told the Commons in 1975 that "we in parliament, who believe in making life better for women … believe that our aims must be translated into laws, which will be binding not merely on the present government but on future governments." In 1975, she also introduced the Balance of Sexes Bill with the objective to require men and women on public bodies in equal numbers. She had identified 4,500 jobs appointed by Ministers, and 174 public bodies that were almost entirely male. In her speech to introduce the second reading of the Bill, she commended changes that had been made to the nominations process for the 'central list' from which candidates for government bodies could be selected, although she doubted that it was sufficiently broad to encourage applications from all areas of society. The Bill did not become law.

In 1976, Colquhoun was among nine Labour MPs advocating in a letter to The Times an "alternative policy" on Northern Ireland, including the removal of British troops from the country.

In December 1976, Colquhoun punched a car park attendant in a row about a parking ticket.

Colquhoun drew a negative response from members of her constituency party, in an area with a significant non-white population, for appearing to defend Enoch Powell in January 1977. "I am rapidly concluding", she said, "that Mr Powell, whom I had always believed to be a racialist before I went into the House of Commons, is not one". She thought that sometimes it was wrong for members of her party to stop listening to what he was saying, and that the "real bogeymen are in the Labour Party" who do not improve the conditions for people in the multi-racial inner-cities. In February 1977, she expressed regret for her comments to her constituency party, withdrew any suggestion she supported Powell's opinions, and affirmed her support for a multi-racial society.