David Robert Peterson, PC was the twentieth Premier of the Province of Ontario, Canada, from June 26, 1985 to October 1, 1990. He was the first Liberal premier of Ontario in 42 years.

Peterson is married to actress Shelley Peterson, and is the younger brother of Jim Peterson, formerly a federal Liberal MP and cabinet minister. Both his sister-in-law Deb Matthews and Tim Peterson, a third brother, were elected to the Ontario legislature in the 2003 provincial election. He has three children named Benjamin Peterson, Chloe Peterson and Adam Peterson.