Britain's EU referendum will be held June 23
The announcement came immediately after Cameron held a meeting with each of his cabinet members where he attempted to convince them that the new EU deal he secured in Brussels on Friday was a good one.
Cameron emerged from the meeting saying the cabinet had agreed with the government's position to recommend that Britain remains in a reformed EU.
"The choice goes to the heart of the kind of country we want to be and the future we want for our children," he said outside 10 Downing Street. "This is about how we trade with neighbouring countries to create jobs, prosperity and financial security for our families."
But not everyone in the cabinet is in favour of staying in the EU. Now that a date has been set for the EU referendum, cabinet ministers are able to campaign in an individual capacity for whichever side of the fence they sit on.
Up to six cabinet ministers are expected to come out against Cameron, saying they want to leave the EU. The majority, however, are expected to back him and campaign to stay in.
International Development Secretary Justine Greening has confirmed she will vote to remain in the EU, as will Business Secretary Sajid Javid and Paymaster General Matt Hancock.
Commons leader and former Justice Secretary Chris Grayling will back the 'out' campaign. Energy Secretary Andrea Leadsom will also back an exit.
Ahead of the cabinet meeting, Home Secretary Theresa May, a cabinet minister that was on the fence about staying in the EU, came out in favour of staying in.
The EU deal, which came at the end of two days of intense talks with EU leaders, gives the UK the power to limit some EU migrants' benefits, including child benefit and in-work benefits.
The deal, which also allows Britain to opt out of an ever-closer union, was reached at a summit of the 28-nation bloc's leaders. Cameron, who is reluctant to sign up to certain EU policies, including the euro currency, said the deal secured "special status" for the UK in Europe.