Stewart was elected as an SNP MSP for the West of Scotland in 2003 and re-elected in 2007.
Between 2003 and 2007 he was a member of the Justice 1 (2003-2004), Justice 2 (2004-2006), Enterprise & Culture (2006-2007) and the Subordinate Legislation (2003-2007) Committees.
Between 2003 and 2007 Stewart was the Group Secretary for the SNP Parliamentary Group. In 2004 Stewart was appointed to the post of Shadow Deputy Minister for Health and in 2006 he was promoted to the Shadow Cabinet as Shadow Minister for Sport, Culture and Media.
Stewart attended King's Park Secondary School before graduating from Glasgow College of Technology with a BA Honours Social Sciences.
Prior to becoming an MSP, he worked for Strathclyde Fire Brigade as Project Manager on the Brigade's Management Information System. He joined the SNP in 1992.
Stewart was born in Glasgow in 1963 and is married with one daughter.