The Communist Party of Canada (Ontario) fielded six candidates in the 2003 Ontario general election.
Candidates
{| class="wikitable sortable" width="100%"
|-
!Riding
!Candidate's Name
!Occupation
!Votes
!%
!Rank
!Notes
|-
|Bramalea—Gore—Malton—Springdale
|
|Writer, translator, and office worker.
|503
|1.19
|6th
|
|-
|Hamilton East
|
|Retired steelworker.
|380
|1.24
|5th
|
|-
|Ottawa Centre
|
|University worker and president of a Canadian Auto Workers local.
|306
|0.62
|5th
|
|-
|Parkdale—High Park
|
|Teacher-in-training.
|349
|0.88
|6th
|Not to be confused with the Canadian Broadcasting Corporation journalist of the same name.
|-
|Scarborough Centre
|
|Party leader and former school trustee.
|241
|0.58
|7th
|Became leader of the Communist Party of Canada in 2016.
|-
|York West
|
|Criminal lawyer
|408
|1.76
|5th
|Has represented accused war criminals from Rwanda and the former Yugoslavia. Joined the Communist Party due to his opposition to the 1999 NATO bombing of Yugoslavia.
|-
|}
Source for election results: Election Results, Elections Ontario, accessed 2 November 2021.