Representatives of Associated British Ports and Dong finalised the deal which will see the construction of a new harbour and pontoon facilities as well as new offices and a warehouse.
Work on construction will begin in January, with completion expected by the end of 2014.
Dong is set to start installing the 35 Siemens 6MW turbines - the first commercial deployment of the machines - in the North Sea in July.
The Danish company received a £1.1 million (EUR 1.3 million) grant from the Humber Local Enterprise Partnership to go towards its £11.5 million investment in the new base.
The port at Grimsby is already home to other operators, including Siemens, Centrica, E.on and RES Offshore. Dong claimed that the development would create 100 jobs in the town.