Vaugier has had recurring roles as Detective Jessica Angell on CSI: NY, Mia on Two and a Half Men, Dr. Helen Bryce on Smallville, FBI Special Agent Emma Barnes on Human Target, and as The Morrigan on Lost Girl.

In feature films, Vaugier appeared, albeit in a minor role, alongside Michael Caine and Robert Duvall in Secondhand Lions.

She starred as Addison in Saw II, reprising her role in Saw IV, and had a supporting part in the Josh Hartnett film 40 Days and 40 Nights.

She also appeared in the Emmy Award nominated miniseries The Beach Boys: An American Family where she portrayed Mike Love’s wife, Suzanne.

From 2005–2015, Vaugier guest starred in twelve episodes of CBS's hit sitcom Two and a Half Men as Mia, a ballet teacher with whom Charlie Harper fell in love and almost married.

She first became noticed by the science fiction community when she portrayed Dr. Helen Bryce, the love interest of Lex Luthor, on the WB's hit drama Smallville in 2002–2003.