John Otho "Jack" Chapman (August 19, 1931 – March 6, 2011) was a power plant supervisor and political figure in Saskatchewan. He represented Estevan from 1980 to 1982 in the Legislative Assembly of Saskatchewan as a New Democratic Party (NDP) member.He was born in Estevan, Saskatchewan and worked 35 years for SaskPower as a power engineer and plant supervisor. Chapman also served on the board for Luther College.