Aberdeen City Council

McDonald was elected to Aberdeen City Council in 2007 at the age of 26 representing the Dyce/Bucksburn/Danestone ward. Twelve days later his colleagues elected him as vice-convener of the housing and environment committee and he was appointed the deputy leader of the SNP group on the council.^[6]

Scottish Parliament

McDonald was elected to the Scottish Parliament in the 2011 election from the North East Scotland regional list^[7] with the SNP taking 52.71% of the vote. As the Scottish National Party had already won all ten constituency seats in the region, it came as a surprise to McDonald, who famously appeared at the declaration wearing jeans and a T-shirt.^[7] He made his maiden speech on 2 June 2011 during a debate on Green Energy. McDonald has been a member of many committees in the parliament, but most recently sat on the Finance Committee and the Devolution & Further Powers Committee. In addition, he served on a number of Cross Party Groups (CPGs) including Oil & Gas, Carers, Epilepsy and Mental Health (which he co-convenes). He served as a Parliamentary Liaison Officer to the Deputy First Minister, John Swinney having previously been Parliamentary Liaison Officer to Alex Salmond during his tenure as First Minister.

In September 2011, McDonald announced he was to bring forward a Member's Bill on High Hedge Disputes,^[8] which was passed unanimously by the Scottish Parliament on 28 March 2013,^[9] making McDonald's bill the first Members' Bill to pass in the Parliamentary session.

McDonald has been a keen advocate for individuals on the autistic spectrum, leading members debates on the issue and asking questions of the Scottish Government. He has been a member of the Scotland Advisory Committee of the National Autistic Society and a trustee of the charity, Friendly Access, which looks to create a more accessible environment for individuals with sensory disabilities.

Following the death of Brian Adam in April 2013, Mark McDonald was selected as the SNP candidate for Aberdeen Donside and resigned his seat as a North East Scotland Region MSP to fight the by-election.^[10] McDonald held the seat for the SNP with a reduced majority and was returned to the Scottish Parliament on 20 June 2013.^[11]

In the 2016 Scottish Parliament election, McDonald contested the seat and was successfully re-elected winning 56% of the vote and increasing the SNP majority to 11,630 – the largest majority in the whole of Scotland.

Scottish Government

Following the Scottish Government reshuffle on 18 May 2016, McDonald was appointed to serve as Minister for Childcare & Early Years.

In March 2020, McDonald announced his plans to step down from parliament at the 2021 election.

Resignation from the SNP

McDonald tendered his resignation as minister on 4 November 2017 following the announcement by the SNP that he was being investigated for misconduct in the wake of the 2017 Westminster sexual misconduct allegations, saying "It has been brought to my attention that some of my previous actions have been considered to be inappropriate – where I have believed myself to have been merely humorous or attempting to be friendly, my behaviour might have made others uncomfortable or led them to question my intentions."^[3]

Two weeks later, McDonald was suspended from the SNP pending an internal investigation. After that investigation substantiated the charges, McDonald announced that he had resigned from the SNP ahead of a group meeting to decide on reinstating him. However, he intended to remain at Holyrood as an independent, despite all major parties in the chamber urging him to stand down.^[4]

On 21 June 2018 the parliament's standards committee recommended McDonald be suspended without pay for a month.^[12]