Karlis is a graduate of the VCA School of Drama, and has worked in theatre, film, TV and music theatre for over 30 years.

In 2025, Karlis appeared in a highly successful season of his self-penned and produced show Loving The Alien at Arts Centre Melbourne ; a narrative concert featuring the songs of David Bowie. He toured in Vidya Makan, Heidi Maguire & Hayes Theatre’s new
Australian musical The Lucky Country (nominated for a 2025 ARIA Award, and a Sydney Theatre Award) for Melbourne Theatre Company, and Brisbane Powerhouse. He can be heard on the cast recording of the show.

Other recent work includes: touring for Complete Works in As You Like It, Twelfth Night, The Tempest, Uncle Vanya, and A Winter’s Tale, Romeo & Juliet for Melbourne Shakespeare Co, and Blood In The Water at La Mama. Karlis narrated an audiobook in a Lithuanian accent (close to his Polish heritage) for Phillip Maisel's remarkable autobiography Keeper Of Miracles (Spotify/Amazon) and appeared alongside Hugo Weaving in the feature film Lone Wolf (Screen Australia/MIFF/Future Pictures)

During the 2020-21 COVID pandemic, Karlis was fortunate to tour South Korea in the 40th Anniversary production of Cats, which was the only major production to open in the world at the time, and was the focus of the Apple TV documentary The Show Must Go On.

Other notable credits include : My Fair Lady, directed by Dame Julie Andrews (Opera Australia/Gordon/Frost), War Horse (National Theatre of Great Britain/Global Creatures), Les Misérables (Asia/South Africa/Aus, Cameron Mackintosh), The Drowsy Chaperone, Scrimshander (MTC), Macbeth (Essential Theatre), Coriolanus (Theatreworks), Jesus Christ Superstar (Harry M Miller), Picnic At Hanging Rock (Foxtel), Preacher (Stan/AMC), Miss Fisher's Murder Mysteries (ABC TV), and his own original dark cabaret Australian Gothic and The Beautiful Losers (winner of 3 Green Room awards).