[2] Blanchard's career was launched with a part in a McDonald's commercial,[1] and as an eight-year-old on the Canadian children's show The Kids of Degrassi Street,[3] in which she played Melanie Schlegel.

[4] Blanchard played the part of Cher Horowitz (originally portrayed by Alicia Silverstone in the film version) in the television series Clueless (based on the 1995 movie of the same name).

Blanchard had notable turns in fellow Canadian director and auteur Atom Egoyan films, first with Where the Truth Lies (2005), then as protagonist Rachel in his Cannes celebrated Adoration (2008), winner of that year's festival Ecumenical Jury Prize.

[7] Blanchard appeared as Nancy, the American girlfriend of main character Jeremy Usborne (Robert Webb), in the second series of British sitcom Peep Show.

[8] She played Sally on the HBO show Flight of the Conchords[9][10] and had a recurring role in the first season of the 2014 FX crime series Fargo.