Maurice Donald Williamson (born 6 March 1951) is a New Zealand politician and former diplomat.

Williamson had a 30-year career as the National Party Member of Parliament for Pakuranga in the New Zealand House of Representatives. During this period, he was a minister in both the Fourth and Fifth National Governments, including as Minister of Transport, Minister of Broadcasting, Minister of Local Government, Minister of Customs and Minister of Statistics.

After retiring from Parliament, Williamson was New Zealand consul-general in Los Angeles from 2017 to 2021. He returned to politics in 2022, successfully contesting the Howick ward of Auckland Council.

Williamson was a member of Parliament for the National Party, a centre-right political Party in New Zealand, as MP for Pakuranga since the 1987 general election. He held a number of ministerial posts, including Minister of Communications, Minister of Broadcasting, Minister of Transport, and Minister of Research, Science and Technology, and associate Minister of Health (1990–96). He was a strong supporter of reform of prostitution law.

His 2005 election campaign saw one of the strongest results for National across New Zealand.

He was suspended from caucus on 22 July 2003, after refusing to curtail his criticism of the National Party leader, Bill English, who he blamed for poor performance in the polls. After English was replaced by Don Brash, Williamson was reinstated. After his return from suspension, Williamson played an active role in National and was elevated up the ranks to eighth position in the National lineup in 2008.

On 1 May 2014, he resigned his ministerial portfolios after making what the Prime Minister, John Key, called, "A serious error of judgement." The Prime Minister was referring to a phone call Mr Williamson had made to the police enquiring about a charge they were laying against businessman and National Party donor Donghua Liu over domestic violence allegations. Williamson had told police he was not trying to interfere with the process – he just wanted to make sure somebody had reviewed the matter to ensure the police were on solid ground as "Mr Liu is investing a lot of money in New Zealand".

Williamson became known for his candid remarks and humor which often attracted controversy. In 2011, he attracted controversy for making crude jokes during a speech addressing a conference audience. Speaking to a Samoan speaker, he joked about whether his "papers were in order". Later he said: "What is the difference between Muslims and Kiwis? Muslims get to commit adultery and get stoned, Kiwis get stoned and commit adultery". In 2015, Prime Minister John Key defended him as a "flamboyant" person with a "strong sense of humour" after Williamson was accused of making "sexist" remarks during another speech. He later apologised. Earlier in 2007, Williamson was slammed for an email he sent in response to a TV report on obesity: "If some people can't lose weight no matter what ... how come there were no fat people in the Nazi concentration camps?"