The son of a miner, he left school aged 15 and worked as a clerk for a mining company before obtaining a job as a newsreader for a radio station in Kalgoorlie, Western Australia. He subsequently worked for various stations in Perth and Western Australia, in both presenting and producing roles.
He moved to the UK and joined Capital Radio at its inception in 1973, first as a producer of talk programmes, and then presenting Capital Open Line, before making his name as presenter of the morning interview and phone-in show on LBC Radio from 1976 to 1990.
Since 1990 Hayes has appeared on various stations, including presenting the BBC Radio 2 breakfast show "Good Morning U.K." from January 1992 until the end of that year. He was replaced by the show's former host Terry Wogan. He worked on BBC Radio Five Live until 2006, and BBC Radio 4, on various programmes including Not Today, Thank You. He has also sat in for Jeremy Vine on Radio 2.