The office was retitled as the Cabinet Secretary for Net Zero, Energy and Transport in Sturgeon's third administration, as part of her government's effort to tackle the climate emergency.

Following a scandal surrounding the misuse of a Parliamentary iPad while on a family holiday, which incurred £11,000 in roaming charges, Matheson resigned as Health Secretary in February 2024.

He first stood as a parliamentary candidate for the SNP in the 1997 general election, standing for the newly created Hamilton North and Bellshill constituency.

In the 1999 Scottish parliamentary election, Matheson contested the Falkirk West constituency, which was won by the independent Dennis Canavan, who had been rejected by the Labour Party.

He contested the Falkirk West constituency again at the 2003 Scottish parliamentary election, and although it was won again by Denis Canavan, Matheson was re-elected as one of three SNP MSPs for Central Scotland.

[6] Before becoming a Minister, Matheson was actively involved in a number of Parliamentary Cross-Party Groups, including those on Malawi, Sport, Alzheimer's disease, International development, Russia and Taiwan.

[7] He also proposed for the criminal justice system in Scotland to move from prison towards rehabilitation in a bid to reduce re-offending rates.

[14] Matheson was accused of being "invisible"[9] and "closing down questions" amid allegations of gross misconduct and leader of the Scottish Conservatives, Ruth Davidson, raised the possibility he may have acted unlawful.

Matheson claimed that he incurred the charges while completing constituency work, and that he had not been aware that he needed to replace the SIM card in the iPad to switch over to the Scottish Parliament's current mobile contract.

[20] It was subsequently revealed that Matheson had been emailed by Parliamentary officials in February 2022, warning him of the need to update the SIM cards in his devices almost a year in advance of his holiday.

[21] On 19 November, Humza Yousaf re-iterated his confidence in Matheson, describing him as a man of integrity and honesty, and insisted that he had not been misled by the health secretary over the bill.

[22] On 8 February 2024, ahead of the publication of an investigation into the incident by the Scottish Parliament Corporate Body, Matheson resigned as Health Secretary.

The Scottish Parliament Corporate Body's report, published on 14 March, upheld three complaints against Matheson and concluded that he had breached sections 7.3 and 7.4 of the MSPs' Code of Conduct.

[26] SNP Deputy First Minister Kate Forbes subsequently introduced an amendment that re-iterated Swinney's complaints about the investigation into Matheson, but did not attempt to change the sanction.

[29] In November 2024, he submitted an application to stand again as the SNP candidate for Falkirk West in the next Scottish Parliament election, to the disquiet of his constituency party.