"It is with great shock and sadness we share with you our friend and past President Jack Sweeney, his wife Lorraine and granddaughter Erin were victims of todays [Monday's] tragedy in Glasgow," reads a post on the Bramalea Celtic Supporters Club's website.
"Our thoughts and prayers go to the family and friends of the Sweeney family."
Celtic is Glasgow's professional soccer club. The soccer appreciation club is based in Brampton.
Ten other people were injured in the accident in Scotland. Six are still in hospital.
Authorities in Glasgow have said the incident was "a road traffic accident, nothing more sinister."