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.[1] He defeated Grant Devine in a 1980 by-election to win a seat in the provincial assembly after Robert Larter resigned from the assembly, citing health reasons.[2] He was defeated by Devine when he ran for reelection in 1982.[3] He died in 2011.[1]