Since Dad, Tierney has written and directed the feature films Twist (2003), for which he was nominated for a Genie Award for Best Adapted Screenplay, The Trotsky (2009), which garnered him two Canadian Comedy Awards and a Genie Award, Good Neighbors (2010), and Preggoland (2014). He has also directed episodes of the television sitcom Mr. D and Gavin Crawford's comedy special Gavin Crawford's Wild West. In 2012, Tierney participated in the jury of the Air Canada enRoute Film Festival.