Sited 32km off the Lincolnshire coast and potentially containing 288 turbines, Triton Knoll is the largest and the last of five projects in the Greater Wash to gain planning permission.
Development was delayed by the Ministry of Defence objecting to the clutter effect of the turbines' blades on its air defence radar screens.
The impasse was finally broken by the five developers stumping up £16 million for a new Lockheed Martin radar system capable of filtering the movement of wind turbines from other air activity.
According to Decc, Triton Knoll will create 1,130 jobs and provide inward investment to the UK of £3.6 billion. When completed, and construction is not scheduled to start until 2017, it will generate power for more than 800,000 homes.
"We have provided certainty early to wind investors and now see significant investment decisions being made that will benefit the UK's economy for years to come," said energy secretary Ed Davey.