Billy Mahonie, a British post-rock band, formed in London in 1997. Their first release was the split single, "Hoon", with Rothko on the Fierce Panda record label. In 1999, they signed with Too Pure and released their debut album, The Big Dig. The band recorded two Peel Sessions that year and toured Europe. In 2001, they released the double album What Becomes Before on Southern Records. Bassist and guitarist Hywell Dinsdale and bassist Kenny Penney left in 2002, leading to a new lineup with Duncan Brown on bass and Anthony Barratt on guitar. The band continued with albums like Dust (2004) and Found (2005) before releasing BM in 2009. The original lineup reunited for shows from 2009 to 2019, culminating in the release of their fifth studio album, Field of Heads, in 2024 on Whistling Sam Projects.