Stewart is a graduate of Huron Heights Secondary School. He received a Bachelor of Applied Arts degree in Radio and Television Arts from Ryerson Polytechnical Institute (now Ryerson University) in 1989, making him the only member of Barenaked Ladies to have earned a degree.

Stewart’s wife, Jill (née Spratt), is a former high school French teacher, and the two were married on September 19, 1998; they have three daughters, Mili, born April 2, 1999, Hazel, born April 16, 2001 and Carmen, born January 28, 2011. In his spare time, he enjoys cooking. He is a huge hockey fan and actively promotes Women’s Hockey in Canada, serving on the board of The Ladies First Hockey Foundation and coaching his daughters’ teams, one being The George Bell Titans. Stewart also went to high school with former Leafs goalie Curtis Joseph where the two became friends. He also enjoys playing hockey, and is a member of the Jokers Hockey Club in the Canadian Exclaim! Hockey Summit of the Arts. Stewart is also an occasional panelist/contributor on the post-game show for Hockey Night in Canada, and an on-air contributor to the morning show on The Fan 590. He took part in Super Skate, a celebrity hockey game fundraiser at Madison Square Garden for the Christopher Reeve Foundation in 1999, 2001 and 2002. Participants included Denis Leary, Kim Alexis, Rick Moranis, Chris Jericho, Gary Dell’Abate, Chad Smith, Darren Pang and Jason Priestley, among others. Stewart is a member of the Canadian Charity Artists Against Racism and has worked with them on campaigns like radio PSAs.

Prior to his switch to SONOR in early 2015, Tyler played Pearl Drums from mid-2006. Stewart used custom Ayotte drums from at least 1994, and prior to that, Canwood drums.