De Boer's television debut was an uncredited role in Freddy the Freeloader's Christmas Dinner, which starred Red Skelton and Vincent Price. Her first major television work was in the CBC series 9B, followed by a recurring role on the Canadian Sketch comedy show The Kids in the Hall as Laura, girlfriend of Bobby Terrance (Bruce McCulloch). She subsequently appeared (as a different character) in their 1996 film Brain Candy.
She starred in the short-lived 1997 SyFy Channel series Deepwater Black (also known as Mission Genesis) as Yuna. This was followed by a role in the film, Cube (1997). She was featured in two episodes of the Canadian-produced series The Outer Limits.
De Boer's other roles have included Ezri Dax on Star Trek: Deep Space Nine (seventh season, 1998–1999), and as Sarah Bannerman on the series The Dead Zone (2002–2007).
