Walker was born in Bendigo, Victoria. He grew up in Melbourne and Brisbane. He dropped out of art school in 1976 and began writing about music for student newspapers and punk fanzines. He DJ'd a punk show on Melbourne's fledgling public radio station 3RRR, before settling in Sydney, where he freelance for rock magazines RAM and Rolling Stone. He currently appears as presenter of the late-night TV live-music show Studio 22, and is working on a new project called Golden Miles.