Popper began his career in the television industry, working for The Comic Strip. Later, he was employed as a Commissioning Editor for Entertainment and Comedy at Channel 4. His commissioning credits include the series Bo' Selecta!, Black Books, Spaced and Bremner, Bird and Fortune. He also commissioned three series of the Comedy Lab whilst at the channel. During this time, he also made his first appearance as a comedian on The Eleven O'Clock Show. He left the role to work on the first series of Look Around You with Peter Serafinowicz. Look Around You was a spoof educational science comedy which ran on BBC2. It was nominated for a BAFTA and a British Comedy Award. Look Around You was written and produced by Robert and Peter. They also wrote and played all the music on the series. Robert co-wrote the short film Hello Friend with Graham Linehan, also in 2003.
Popper had a small, uncredited role in Shaun of the Dead, in which he played a news reporter and appears in the follow-up Hot Fuzz, credited as 'Not Janine'.
He is also the script editor for the fourth series of Bo' Selecta!, and producer for the third series of Peep Show.
In 2005, he returned to the screen with a second series of Look Around You. Made up of six half-hour shows, it resembled an early 80s Tomorrow's World and, besides Robert and Peter, featured Josie D'Arby and Olivia Colman as presenters. The show won the Rose D'Or TV Award in 2006 for Best Comedy Series.
Robert Popper is a regular contributor to "Jack Magazine" and the US magazine "Methicamay".
Robert wrote The Timewaster Letters and The Return of the Timewaster Letters under the pseudonym, Robin Cooper. The books were a set of mad letters he wrote to weird associations and hobby groups. The books became huge bestsellers and have so far sold nearly 300,000 copies.
The Timewaster Diaries was published on 5 July 2007, and was serialised on Radio 4's Book of the Week programme 16-20 July 2007, read by Paul Whitehouse.
Robert worked in LA writing with Sacha Baron Cohen in 2007, and produced series 3 and 4 of Channel 4's comedy Peep Show. Both series won the British Comedy Award for Best Comedy, and Popper won a BAFTA for series 4.
He is currently believed to be working with Peter Serafinowicz on a new show for America. The Timewaster Letters was released in the USA in the summer of 2008 and there have been a number of Robin Cooper Timewaster Phone Calls released on the web.