Roseby grew up in a small village in North West Norfolk, attending one of the biggest comprehensive schools in the East, Smithdon High School, Hunstanton. After leaving home at 16 to study A Levels at Norwich City College he also left any thoughts of any further education to his friends and colleagues by leaving Norfolk to join the NYT in the mid 1980's. There he enjoyed four successful years with the company as a young actor. To pay for it, he sold clothes out of a bag around the streets of London, and then graduated to a market stall in Camden quickly followed by a designer shoe shop (Wayne Hemmingway's first Red or Dead store). With a few hard core fashion looks, and an obligatory social life to go with them, Roseby became a regular contributor on BBC Greater London Radio and LBC, being a gob without a job and reviewing the papers and generally filling in when other people ran out of things to say.
He progressed to BBC Radio 5 (before it was 5 Live) being Danny Baker’s sidekick who never ran out of things to say. TV commercials became his staple diet, and Roseby sold Beer, Margarine and German Furniture on most TV channels across Europe. This paid for his foray in to fringe and touring theatre productions, but left those behind when his first TV break came for Schofield’s Quest on ITV (before it was ITV1) where he had to search for the Beast of Bodmin Moor as an intrepid reporter - it was never clear which of the two was more frightened. Other presenting credits include The Culture Show on BBC 2, and More Fabulous Flops on Radio 4