[4] After working, firstly at Lloyds Bank in Mumbles and then as a teacher, in the 1980s he turned to comedy and moved to London, performing on the alternative cabaret circuit with comedians such as Alexei Sayle, Jo Brand, Paul Merton, and Rik Mayall.
[1][5] Sparkes starred in the sketch show Naked Video, where he played Siadwel, the geeky South Wales poet who wore an anorak and glasses.
Throughout its original run, the series also won four BAFTA Cymru awards for Best Light Entertainment.
He also voices Mr Elf and King Marigold in Ben & Holly's Little Kingdom, Professor von Proton in The Big Knights, Steven in A Town Called Panic, and the lead character Fireman Sam in the 2005 series.
He has voiced the unseen character of archivist Goronwy, in a section of Wallace and Gromit's World of Invention for BBC One and has written and presented Ghost Story, in which he spent the night alone with a camcorder in haunted houses around Wales.