He is also a founding member of Mercy Arms and has played with the Night Game, Jack Ladder and the Dreamlanders, Mark Ronson and Genesis Owusu.

"[4] Callinan has collaborated with a wide range of musicians, including Mark Ronson,[5] Jimmy Barnes, James Chance, Alex Cameron, Connan Mockasin, Caroline Polachek, Weyes Blood, Pond, Mac Demarco, Martin Johnson, Ariel Pink, Hubert Lenoir, Julian Casablancas, Genesis Owusu, whistler Molly Lewis and brothers Neil and Tim Finn.

[9][10] In 2005, he formed indie rock band Mercy Arms with fellow guitarist and vocalist Thom Moore, bassist Ash Moss, and drummer Julian Sudek.

Beginning in 2016, Callinan began recording and performing with The Night Game, a rock band with Martin Johnson.

He lifted his kilt on the red carpet at the ARIA Music Awards of 2017, briefly exposing his genitals to press photographers.

Writing for the Sydney Morning Herald, music journalist Michael Dwyer declared "Kirin J Callinan has just purloined the concept album of the century".

Since 2009 he has been an original touring member of Jack Ladder & The Dreamlanders, contributing guitars on the 2009 live EP Counterfeits as well as full length albums Hurtsville (2011), Playmates (2014), Blue Poles (2018) and 2021's Hijack!.

He also played guitars on Mark Ronson's Grammy Award winning album "Uptown Special", performing songs from the album including lead singles "Uptown Funk" and "Leaving Los Feliz" live alongside Ronson and Tame Impala's Kevin Parker.

[22] Back in Australia, Callinan also begun working alongside Australian / Ghanaian rapper Genesis Owusu, co-writing 2021's Smiling with No Teeth album, contributing vocals and guitar.