In October 2001, Mack began starring as Chloe Sullivan, one of Clark Kent's best friends, in the WB/CW hit series, Smallville; Chloe, an original character created solely for the show, was eventually introduced into DC Comics in 2010.
Mack earned several awards and nominations for her portrayal of Chloe, including the Teen Choice Award for Best Sidekick in 2006 and 2007.
She appeared as a series regular for nine seasons, and returned as an intermittent main cast member in the tenth and final season including the two-part series finale.
From 2003–2004, Mack's character appeared in her own miniseries titled Smallville: Chloe Chronicles, and in 2006, Smallville: Vengeance Chronicles.
In November 2008, Mack made her directorial debut in Smallville season 8 episode 13 titled "Power", which aired January 29, 2009.

In 2002 she made a couple of appearances along with her Smallville castmate Sam Jones III in R. L. Stine's miniseries The Nightmare Room.

In 2006, Mack voiced the sister of the main character in the Warner Bros. CG-animated movie The Ant Bully.
That same year, she voiced Clea, a museum curator in an episode of The Batman.
Adding to her Superman resume, she lent her voice for Power Girl in the Warner Premiere animated feature, Superman/Batman: Public Enemies, in September 2009.
Since May 2009, Mack has been part of a project with the Iris Theatre Company.
In October 2001, Mack began starring as Chloe Sullivan, one of Clark Kent's best friends, in the WB/CW hit series, Smallville; Chloe, an original character created solely for the show, was eventually introduced into DC Comics in 2010. Mack earned several awards and nominations for her portrayal of Chloe, including the Teen Choice Award for Best Sidekick in 2006 and 2007. She appeared as a series regular for nine seasons, and returned as an intermittent main cast member in the tenth and final season including the two-part series finale. From 2003–2004, Mack's character appeared in her own miniseries titled Smallville: Chloe Chronicles, and in 2006, Smallville: Vengeance Chronicles. In November 2008, Mack made her directorial debut in Smallville season 8 episode 13 titled "Power", which aired January 29, 2009.
In 2002 she made a couple of appearances along with her Smallville castmate Sam Jones III in R. L. Stine's miniseries The Nightmare Room.
In 2006, Mack voiced the sister of the main character in the Warner Bros. CG-animated movie The Ant Bully. That same year, she voiced Clea, a museum curator in an episode of The Batman. Adding to her Superman resume, she lent her voice for Power Girl in the Warner Premiere animated feature, Superman/Batman: Public Enemies, in September 2009. Since May 2009, Mack has been part of a project with the Iris Theatre Company.
Allison Mack