Service will begin after the airline receives its third double-decker A380, the largest airliner ever built, SIA said.
SIA currently files two A380s between Singapore and Sydney after commencing service in October.
"For the first time, an aircraft larger than the B747-400 will fly this route, thereby meaning more seats without the need for more frequencies to what is already one of the world's busiest airports," said Huang Cheng Eng, SIA executive vice president for marketing and the regions.
Flights will land at London's Heathrow Airport.
Passengers on board the inaugural London flights will receive personalised certificates, souvenirs and "exclusive premium giveaways", SIA said.
The giant plane can carry up to 853 passengers but SIA, one of the world's most profitable airlines, chose a setup with a maximum 471 seats.
The design includes 12 "Suites", each with a full-length bed behind sliding doors, sheets by French design house Givenchy and flat-screen televisions.
SIA has committed to buy a total of 19 A380s.
Singapore Airlines executives have said service to Japan could come after London.
Dubai-based Emirates has ordered 55 A380s, making it the leading client on a list of predominantly Asian, European and Gulf-based customers for the plane. Australia's Qantas is to get the A380 this year for use on its Los Angeles route.
AFP