The supply contract will cover engineering, procurement, assembly, and offshore commissioning for the 67 turbine site off the Norfolk coast.
Engineering work will commence this month, with the first set of turbines due to be ready for installation by January 2017.
The service contract will cover operations and maintenance of the turbines through the first two years after installation, and a further three years where Siemens will provide Dudgeon with technicians and other services.
The 402MW Dudgeon offshore windfarm is a joint venture between two Norwegian companies, Statoil, which has a 70 per cent stake, and Statkraft, which has a 30 per cent stake.
Statoil renewable energy senior vice president Siri Espedal Kindem said: “The new turbine contract will secure planned progress in the Dudgeon project towards full operation during 2017.
“Technology development is fundamental to optimising offshore wind industry costs and solutions, and the use of new large turbines such as these is a main contributor to reducing offshore wind costs.”
Statoil offshore wind project vice president Halfdan Brustad, added: “In Dudgeon we seek to optimise solutions even further to bring down electricity costs, and we will have a strong cooperation with Siemens in operation and maintenance to ensure high regularity.”