Diane Johnston is a politician and political activist in Canada. She has campaigned for office at the federal and provincial levels in Ontario and Quebec, as a candidate of the Communist Party of Canada - Marxist-Leninist. In the 1995 Ontario election, she was recognized as the leader of the "Ontario Renewal Party", which was the CPC-ML under a different name.

Johnston has at various times described her occupation as office worker, sales representative, and secretary. She became involved with the Marxist-Leninist Party in the mid-1970s, and has written numerous articles published by the party. In 2002, she wrote an article describing the federal government's Immigration and Refugee Protection Act as racist legislation.

Johnston was 51 years old at the time of the 2003 Quebec election. Running in Quebec, she has described Quebec as a nation and not simply as a Canadian province.

Electoral Record:

• Quebec general election, 1989, Ste-Anne , 70 votes (winner: Normand Cherry , Liberal)
• Ontario by-election, April 1, 1993, Don Mills , 498 votes (winner: David Johnson, Progressive Conservative) [Johnston appeared on the ballot as an independent.]
• Canadian federal election, 1993, York Centre, 83 votes (winner: Art Eggleton, Liberal)
• Ontario general election, 1995, Etobicoke—Rexdale , 488 votes (winner: John Hastings, Progressive Conservative) [Johnston appeared on the ballot as an independent.]
• Canadian federal election, 1997, York Centre, 168 votes (winner: Art Eggleton, Liberal)
• Ontario general election, 1999, Etobicoke North, 489 votes (winner: John Hastings, Progressive Conservative) [Johnston appeared on the ballot as an independent.]
• Canadian federal election, 2000, York Centre, 142 votes (winner: Art Eggleton, Liberal)
• Quebec general election, 2003, Westmount—St-Louis , 64 votes (winner: Jacques Chagnon , Liberal)
• Canadian federal election, 2004, Mount Royal, 94 votes (winner: Irwin Cotler, Liberal)