Directed by Inception's Christopher Nolan, the new World War II thriller Oppenheimer is Murphy's first lead role in a Hollywood blockbuster, with Oscar chatter already in motion.
While promoting the movie, the Irishman delved into his real-life character's distinctive silhouette, revealing: "It's funny because some of the references Chris sent me were like, of David Bowie.
"You know, some of those high-waisted, very voluminous trousers like Bowie in The Thin White Duke or 'Young Americans' era. And he was so slim and so kind of gaunt-looking, so that was part of the inspiration - unlikely inspiration."
Interestingly, Nolan and Bowie previously worked together on The Prestige, where the late rockstar portrayed inventor Nikola Tesla.
To reach that level of boniness we see on screen, Murphy found help in the Oppenheimer filming schedule.
He told The Guardian: "It's like you're on this f***ing train that's just bombing. It's bang, bang, bang, bang. You sleep for a few hours, get up, bang it again.
"I was running on crazy energy; I went over a threshold to where I was not worrying about food or anything."
Based on the 2005 biography American Prometheus, the movie also features Robert Downey Jr as chairman of the US Atomic Energy Commission, Lewis Strauss; Emily Blunt as Kitty Oppenheimer; Florence Pugh as Jean Tatlock, Matt Damon as Leslie Groves, Gary Oldman as Harry S. Truman, Rami Malek as David Hill, and Tom Conti as Albert Einstein.
Oppenheimer is out now in cinemas.
Watch: Cillian Murphy has likened the Oppenheimer set to working in a "laboratory"