Born in Dunfermline in 1962, Wishart was educated at Queen Anne High School Dunfermline and Moray House College, Edinburgh. Wishart lives in Perth and has one son and enjoys walking in the Perthshire hills. Wishart is a trained community worker and has been a director of the Fast Forward charity that promotes healthy lifestyles for young people. He was a member of the Scotland Against Drugs Campaign Committee and has contributed to many national forums looking at the problem of drugs within Scottish society.

After the departure of Richard Cherns in February 1986, Wishart joined Runrig. Wishart was a performer on seven of Runrig’s studio albums, from The Cutter and the Clan (1987), to his last The Stamping Ground (2001). He also appears on several of Runrig’s live albums. Wishart’s tenure in the band coincided with their sign-up to the Chrysalis Records label, and their most successfully commercial period in the late eighties and early nineties. Wishart was not the only politically minded member of the band – former lead singer Donnie Munro became a Labour Party candidate.

In November 2010, Wishart suggested that Scottish football referees should declare which club sides they support.

In January 2015, Wishart secured and started a debate on the reform of the House of Lords.

Following the 2015 general election, it was announced in June 2015 that he would chair the Scottish Affairs Select Committee, with his appointment formally announced on 19 June 2015. At the snap 2017 general election, he retained his seat by a very marginal majority, beating Conservative Ian Duncan by just 21 votes.

In 2016, Wishart suggested to the House of Commons the possibility of the Palace of Westminster being turned into a tourist attraction and for Parliament to move to a more modern building.

Wishart said publicly in September 2017 that because voters were “weary of constitutional change” there should be no second referendum on Scottish independence for that parliament, but that the SNP should seek a mandate for a new one in the 2021 Scottish parliament election. In October 2017, Wishart told an Institute of Economic Affairs conference that federalism for the UK should be welcomed “as part of that conversation” in Scotland, although he stressed federalism would not see Scotland “equal to some region of England”.

In January 2018, Wishart drew media attention for holding up a placard which read “nul points” in the House of Commons, after having asked Prime Minister Theresa May how she would rate her government’s handling of Brexit from one to ten. After May had answered, Wishart received a warning by Speaker of the House John Bercow for the stunt.

In February 2018, he warned that the SNP risked alienating Scottish voters who had voted “Leave” in the 2016 referendum on European Union membership. In an article for The National, he wrote that his party had to “face up” to the reality that Scotland would be leaving the European Union, and made the case for an alternative vision of Scottish independence which involved a “graduated” re-entry to the European Union from “EEA, then EFTA then full EU membership”, stressing that the final step of rejoining the EU should only be done with the “full consent of an independent Scottish Parliament”. Later in February, he ruled himself out of the 2018 Scottish Depute Leadership election following the resignation of Angus Robertson. Wishart concluded that he did not have “sufficient support” to run for the Depute Leadership of the Scottish National Party.