His Sydney Theatre Company credits include The School for Scandal directed by Judy Davis, the premiere and national tour of David Williamson's The Great Man directed by Robyn Nevin, and leading roles in George Bernard Shaw's Major Barbara, Andrew Upton's Hanging Man, Tony McNamara's The Great, Brendan Cowell's Self Esteem, Nina Raine's Rabbit and Tom Stoppard's Travesties.

[4] His many television credits include McLeod's Daughters, The Heartbreak Tour, The Cooks, White Collar Blue, Water Rats, Fat Cow Motel (ABC), Home and Away, Temptation, and the Steven Spielberg/Tom Hanks produced miniseries The Pacific.

He also be appeared in the third instalment of the Underbelly Files series of telemovies, titled 'The Man Who Got Away', portraying notorious drug smuggler and organised crime figurehead David McMillan.

In 2014, Schmitz joined an ensemble cast in the Starz dramatic series Black Sails as historical pirate Calico Jack Rackham.

In 2017, Schmitz starred in the ABC legal drama Newton's Law opposite Claudia Karvan, appearing as the SC Lewis Hughes.

After a solid grounding in writing revue and stand-up comedy at university in Perth, Schmitz wrote his first play, dreamalittledreamalittle, while studying acting at NIDA.