The SNP’s former Westminster leader between 2007 and 2017, he lost his seat in the snap election called by Theresa May to the Conservatives’ Douglas Ross in the Moray constituency.
Since his departure from Westminster, Mr Robertson has worked as the managing director of pro-independence think-tank and polling organisation Progress Scotland.
Mr Robertson, who was also the depute leader of the SNP between 2016 and 2018, won the Edinburgh Central constituency seat with a majority 4,732.
The constituency was previously held by the former leader of the Scottish Conservatives, Ruth Davidson, who did not seek re-election as she will be heading to the House of Lords after accepting a peerage.
A prominent figure throughout the campaign after taking over as Scottish Conservative leader from Jackson Carlaw in August last year, Mr Ross will take his seat after being elected as a list MSP for the Highlands and Islands.
It isn’t the first time Mr Ross has been at Holyrood however – he was previously a regional MSP for the Highlands and Islands between May 2016 and June 2017 before resigning his seat after winning the Moray constituency in the 2017 UK general election.
Last year, Mr Ross resigned as a Scotland Office minister in Boris Johnson’s government following controversy surrounding Dominic Cummings’ trip to Durham during the first coronavirus lockdown across the UK.
A qualified football official, he faced criticism for missing a vote in the Commons on Universal Credit whilst working as an assistant referee during a Champions League fixture in 2017.
He is still an MP for Moray and has indicated that he will not resign his Commons seat, although he pledged to not take a salary from his Holyrood role.
Elected as an MP in 2017 when Scottish Labour increased their seats in Scotland from one to seven during Jeremy Corbyn’s leadership of the party at UK level.
He represented the Glasgow North East constituency and served as Labour’s shadow minister for Scotland, before losing his seat in the 2019 election to the SNP’s Anne McLaughlin.
Last year, Mr Sweeney spoke about applying for Universal Credit after finding himself unemployed during the coronavirus pandemic.
A recent departure from Westminster, Mr Gray resigned as the MP for Airdrie and Shotts in March, having held the seat since 2015.
His re-election triggers a by-election for the seat, which will be held on Thursday May 13.
Throughout his time at Westminster, Mr Gray served as the SNP’s spokesperson for work and pensions.
In his final speech in the Commons, he said his decision to resign as an MP had been motived by a desire to be “closer to home to be a good father, and being in the constituency more”.
Won her seat at Holyrood with 47.3% of the vote as the SNP held the Falkirk East constituency.
Ms Thomson was the MP for Edinburgh East between 2015 and 2017 before losing her seat to the Liberal Democrats’ Christine Jardine.
In her time at Westminster, Ms Thomson briefly served as her party’s spokesperson for business, innovation, and skills.
During a Commons debate focused on UN International Day For The Elimination Of Violence Against Women in 2016, she told MPs that she had been raped at the age of 14, with a visibly moved then-Speaker John Bercow telling her the speech had “left an indelible impression upon us all”.