Politically active since his time as a student, Kretschmann and other like-minded associates founded The Green Party in Baden-Württemberg in 1979. One year later, Winfried Kretschmann became a member of the first parliamentary group of The Green Party to be elected to the State Parliament of Baden-Württemberg. In 1986, he was appointed by Hessen’s Minister of the Environment Joschka Fischer as a policy advisor to the first Green Party Ministry of the Environment. After two years in Wiesbaden, he returned to the Baden-Wurttemberg State Parliament in 1988, where he has remained ever since with only one period out of office. In 2002, Kretschmann was elected Chairman of the Green Party in parliament which he remained until 2011.
On May 12, 2016, Winfried Kretschmann was re-elected Minister-President of Baden-Württemberg in the State Parliament, gaining 82 of 142 votes.
Kretschmann has been married to his wife Gerlinde since 1975. The couple have three adult children. A keen DIY enthusiast, Kretschmann is able to unwind best working around the house and garden or hiking in the hills of the Schwäbische Alb.