Prior to joining the Degrassi cast, he had a two-year run as Pleskit, the alien lead in the television series I Was a Sixth Grade Alien. Cooley's other television credits include the series, Are You Afraid of the Dark?, Queer as Folk, Lexx: The Series and Life with Derek. He has also appeared in the features Sachsenhausen 1944, Toy Men, Disney Channel movie The Color of Friendship, the Animal Planet movie Cybermutt and CBC TV movie Happy Christmas Miss King alongside his Degrassi co-star Lauren Collins. In 2006, Cooley was nominated for a Young Artist Award (LA) the category of Best Performance in a TV Comedy Series
Cooley has also appeared in the 2007 film The Tracey Fragments with Elliot Page.[a] In 2012, Cooley guest starred in a YouTube miniseries called Millie and Midge, in episodes 2 and 4 as Parker.