Los eventos más importantes que toman lugar en Markham son: Youth Festival, Unionville Festival, Markham Village Music Festival, Markham Jazz Festival, Milliken Mills Children's Festival, Thornhill Village Festival, Markham Fair, Markham Festival of Lights, Markham Santa Claus Parade, Olde Tyme Christmas Unionville, Markham Ribfest & Music Festival,Cornell Garden Festival y el Cornell Easter Egg Hunt