[2] Kirk grew up in Union, Washington,[1] where he attended a grade school on a Native American reservation, until his family moved to Minneapolis, Minnesota, when he was 12 years old.

[2][6] Kirk began his career on stage appearing off-Broadway in productions such as The Applicant, Shardston, Loose Ends, Thanksgiving, and Lovequest Live.

He next starred as Stephen Hoffman in Jon Marans’s two-character play Old Wicked Songs, staged at the New York's Promenade Theatre and Los Angeles' Geffen Playhouse.

In 2012, he appeared in the role of Trip Wyeth succeeding Thomas Sadoski in Jon Robin Baitz’s play Other Desert Cities.

In 2020, he began playing the role of Hamilton Burger in the HBO period drama series Perry Mason.

Kirk‘s first appearance on screen was in the 1994 romantic horror film Wolf in a photograph as Laura Alden's deceased brother.

His other film credits include Vamps (2012), Mr. Morgan's Last Love (2013), Justice League: War (2014), Ghostbusters: Extended Edition (2016), Molly's Game (2017), The Tribes of Palos Verdes (2017), and Vice (2018).