The Dutch firm will build the 35-metre-high jacket foundation for the 400MW substation, which will be installed at the Horns Rev 3 project.
Delivery of the 1,300-tonne jacket is scheduled to take place in March 2016. Hollandia previously worked on EWE's Riffgat and Vattenfall's DanTysk offshore substations.
Last week, Energinet.dk, Denmark's transmission system operator, announced that Vattenfall had won the rights to develop the 400MW offshore project, located 10 kilometres off the Danish North Sea coast.
The first turbines at Horns Rev 3 are expected to be connected in 2017.
Vattenfall placed a winning bid of €0.1031/kWh to secure the development contract from the Danish government. The Danish Energy Agency said the amount was far below that of Dong Energy's Anholt project, which had an agreed price of €0.1407/kWh (€0.1515/kWh in 2015 prices).