Lambert, previously head of government affairs at Microsoft, will start the new role in January. He makes the departure after 12 years at the technology giant.
He will report to chief legal and regulatory affairs officer Martin Cruddace.
Lambert said of his appointment: 'Betfair is a great British Internet success story and a company that is really going places so I jumped at the chance to lead its global public affairs team.'
Betfair is the world’s biggest online betting community, having pioneered the betting exchange in 2000. In addition to sports betting, it offers a portfolio of products including casino, exchange games and poker.
Lambert has been charged with overseeing Betfair’s global regulatory and public affairs strategy.
