Oliver was born in Tunbridge Wells, Kent, England. After studying there since 1997, he graduated from the Central School of Speech and Drama in 2000 and he soon appeared in the BBC big-budget adaptation of the classic novel Lorna Doone (2000). He followed this with another BBC Show, The Office (2001), where he appeared as "Ricky Howard" for the first series. Oliver was most recently seen starring in the Channel Four comedy series Green Wing (2004), Nathan Barley (2005) and The IT Crowd (2006). He also made an appearance in the highly anticipated Sharpe: Sharpe's Challenge (2006). Oliver most notably played Nick Medhurst, the ATO for the British army unit Bluestone 42 (2013) in the BBC Three comedy of the same name, Chris played Nick from 2013-15, and appeared in all 3 seasons. It followed his attempts at getting with the patrol base padre Mary while also showing the reality of fighting a war in these times, while also having a heap of fun and banter and comradeship with his unit.