The first same sex couples will be able to marry from Saturday 29 March 2014.
The move, which comes several months earlier than originally expected, follows the successful completion of the Marriage (Same Sex Couples) Act’s journey through Parliament in July 2013. The new legislation applies to England and Wales.
Announcing the date on 10 December 2013, Women and Equalities Minister Maria Miller said: “Marriage is one of our most important institutions, and from 29 March 2014 it will be open to everyone, irrespective of whether they fall in love with someone of the same sex or opposite sex.
“I know that many couples up and down the country will be hugely excited that they can now plan for their big day and demonstrate their love and commitment to each other by getting married.”
Those couples wishing to be among the first to marry will need to formally give notice of their intention to marry by 13 March 2014.
The government said that same sex couples who married abroad under foreign law and were currently treated as civil partners would also be recognised as being married in England and Wales in March 2014.
The government said it was working to ensure that couples wishing to convert their civil partnerships into marriages and married people wanting to change their legal gender while remaining married, would be able to do so as soon as possible and was aiming to achieve this by the end of 2014.