Winstone worked for Virgin Books, overseeing their Missing Adventures Doctor Who series and briefly being in charge of the New Adventures after the series had ceased being a Doctor Who tie-in. His only novel, the New Adventure Where Angels Fear, was co-written with Rebecca Levene, his predecessor on the New Adventures.
Winstone moved into TV in the late 1990s, working on the popular ITV soap opera Emmerdale for a period. He then worked on rival BBC series EastEnders for many years as a story editor and then as a producer. In 2005, Winstone was announced as a script editor for Doctor Who on TV, a role he had until 2007.
He has written for crime drama Death in Paradise and period drama Dickensian, as well as served as an executive producer on the action-adventure series Hooten & the Lady, all Red Planet Pictures productions.
- Levene, Rebecca; Winstone, Simon (1998), Where Angels Fear, Virgin Pub., ISBN 978-0-426-20530-2
- "BBC exec to lead Red Planet's factual arm". C21 media. 25 October 2007. Retrieved 2011-01-29.
- David Williamson, Western Mail (2007-02-21). "Dr Who man lands at city's Red Planet office". WalesOnline. Retrieved 2011-01-29.