Ashton Fletcher Irwin (b. July 7, 1994) is an Australian singer and songwriter. He is the drummer of the pop-rock band 5 Seconds of Summer.

Irwin began playing the drums when he was 9, after asking his step-father, who was a drummer, to teach him. The first song he learned to play was Green Day’s “Holiday.”

In 2011, he was invited by Michael Clifford, Luke Hemmings, and Calum Hood to be the drummer of 5 Seconds of Summer. He joined the group only a few months after the band’s formation.

The band rose to fame in 2014 with the single “She Looks So Perfect,” and ever since then has been gaining significant following and attention. As of 2021, the band has sold over 8 million units.

On September 23, 2020, Ashton announced his debut solo album, Superbloom, scheduled for release on October 23. The album’s lead single, “Skinny Skinny,” was released on the same day, and displays Ashton’s shift in musical sound from 5SOS' signature pop-punk to alternative.