Rossi studied acting at the Lee Strasberg Theatre Institute in New York where he appeared in several theatre productions in the short time he was there. Rossi attended State University of New York Albany during 1994–1998.
Growing up, he loved to ride dirt bikes. Theo Rossi is best known for his portrayal of Juan Carlos "Juice" Ortiz on the Forex #1 hit series Sons of Anarchy. His production company, Dos Dudes Pictures, produced its first feature film in 2014, Bad Hurt, which Rossi also stars in alongside Karen Allen (Indiana Jones: Raiders of the Lost Ark) and Michael Harney (Orange Is the New Black, True Detective).
Throughout his acting career, Rossi has showcased his versatility starring in a multitude of hit television shows such as Law and Order: SVU, Hawaii Five-O, Las Vegas, The Unit, Jericho, Bones, Without a Trace, Veronica Mars, New York City Police Department Blue, Computer Society of India:Miami, and Lie to Maine.
He has had recurring roles on Heist, American Dreams, and Terminator: The Sarah Connor Chronicles. His film credits include Bad Hurt, Cloverfield, Code Breakers", House of the Dead 2: Dead Aim, Red Sands, The Informers, Kill Theory, Fencewalker, and Meth Head.
Rossi formed the New York-based production company Dos Dudes Pictures, which wrapped production on its first feature film, Bad Hurt, in 2014, which will release on February 12, 2016. In 2015, it was announced that Rossi had been cast in Netflix"s upcoming Luke Cage series.