Ian William Rilen (12 August 1947 – 30 October 2006) was an Australian musician. He was bass guitarist and songwriter with Rock N’ Roll band Rose Tattoo, and led punk rock group X while also providing lead guitar, rhythm guitar and vocals. Rilen was born in Bendigo, Victoria, started his musical career in Sydney and later lived in Melbourne.

Rilen was a member of 1970s progressive blues group Band of Light and other bands, including Space, Blue Aliens, Blackfeather, Sardine v, Hell to Pay, Skindiver and Illustrated Men. Rilen wrote one of Rose Tattoo’s biggest hits, ‘Bad Boy for Love’, and co-wrote ‘Stuck on You’ with his first wife Stephanie Falconer, which was covered by Hunters & Collectors. Rilen was diagnosed with bladder cancer early in 2006 and died on 30 October, aged 59. He had five children: Alicia Ann Macfarlane, Jay Jay, Gentilla, Tallulah and Romeo.