Philip Hammond said the games were a "once in a generation" event for the country and that Britain wanted them to be secure for athletes coming from around the world.
He said the military would deploy 5,000 personnel to support police and civil authorities with a 1,000-strong "unarmed contingency force for deployment in the event of an Olympics-related civil emergency."
A further 1,000 military personnel would provide logistics support with up to 7,500 providing venue security.
Helicopter carrier HMS Ocean, which is the biggest warship in the Royal Navy and recently served off the coast of Libya, will be stationed in the River Thames at Greenwich, southeast London, he said.
Amphibious assault ship HMS Bulwark will be stationed in Weymouth Bay off the southern English coast as a control ship.
Typhoon jets, which were also used over Libya, will be temporarily stationed at a Royal Air Force base in north London while helicopters will operate from HMS Ocean.
Hammond said there would also be "appropriate ground-based air defence capabilities also to support the airspace security effort".
"Next year's Olympic and Paralympic Games are once-in-a-generation events for the UK," he said.
"We want them to be secure, so that all those competing and attending can enjoy the Games for the celebration of sporting achievement and cultural celebration that it is."
13,500 troops on duty at London 2012
Advertisement