Lyle Stewart was born and raised near Pense, Saskatchewan, where he continues to farm and ranch.
Lyle was one of the first members in the Saskatchewan Party and was elected to the Legislative Assembly as the MLA for Thunder Creek in 1999. He was re-elected in 2003, 2007, 2011, 2016, and 2020.
During his two terms in opposition, Lyle served as the interim leader of the party, as well as the critic for Agriculture, Economic Development, and Industry and Resources.
After the Saskatchewan Party formed government in 2007, Lyle served as the Minister of Agriculture, Minister responsible for Saskatchewan Crop Insurance Corporation, and Minister for Enterprise and Innovation. He was also chair of the legislature's Standing Committee on the Economy and a member of the caucus policy committee on the economy and the province's Treasury Board.
Lyle has three grown children and five grandchildren.