As part of her role, Jennings is likely to promote the Games in association with official sponsors, including Adidas and Lloyds TSB.
While at O2, where she worked for seven years, Jennings was part of the team that oversaw its deal to sponsor the England rugby team, the O2 Wireless festival and the rebranding of the Millennium Dome to The O2.
She was made head of sponsorship in 2006 following a number of roles across the O2 Group and O2 UK.
Jennings started her career in advertising, with roles at DDB London as well as several digital agencies.
In 2001, she moved to the then BT Cellnet to launch a start-up called Genie, which subsequently became O2.co.uk.
Jennings went on to work on the rebrand of BT Cellnet as O2 before becoming the head of brand experience at O2 UK.
Jennings will now work with Chime Group, which handles the London 2012 communications account. The group houses sports marketing agency Fast Track, advertising agency VCCP, digital agency VCCP Digital and sales promotions agency BMT.