The three contracts cover the 750MW Walney Extension and the 258MW Burbo Bank Extension off the UK's west coast, and the 580MW Race Bank project on the east coast.
The Canada-based consultants will provide engineering support to Dong in designing the three onshore substations.
Construction of the first project is due to begin within the next six months. The Walney Extension is expected online in 2016 with the other two projects set to be commissioned in 2017.
WSP senior technical director, Jon Johnson, said the contracts would help the company improve substation design and help the Danish developer in cutting costs.
British engineering consultancy firm Atkins is designing the offshore substations for the three projects.