Seamus Patrick McGrath (born March 5, 1976, in Mississauga, Ontario) is a retired Canadian professional mountain biker.

[2][3] Growing up in Flamborough, Ontario, McGrath made his official debut at the 2002 Commonwealth Games in Manchester, England, where he joined his teammate Roland Green to take the silver medal and climb on top of the podium for Canada with a spectacular 1–2 finish.

[4] When he first competed for Canada at the 2004 Summer Olympics in Athens, McGrath scored a career-high, ninth place in the men's cross-country race with a time of 2:20:33, finishing just off the podium by a three-minute gap.

[5][6] Two years later, McGrath continued to set another sterling record by picking up the bronze in the same tournament (2:13:43) at the 2006 Commonwealth Games in Melbourne, Australia, trailing behind the British duo Liam Killeen and Oliver Beckingsale within a short riding distance.

Realizing that his new wheel contained a slow leak at the designated site, McGrath decided to end his course with only three laps left and a forty-fourth-place finish.