Siemens UK chief executive Juergen Maier said it was a "proud" day for the company and they had "proved the doubters wrong".
Maier however, said the work had only just begun and ensuring the continued growth of jobs during the "digital industrial revolution" would be "more difficult".
Construction of the factory began in January 2015. It forms part of Siemens' £310 million investment in the port, which will also include turbine assembly area and berths for three installation vessels.
The opening ceremony was attended by the UK's lead energy minister Greg Clark and department of business, energy and industrial strategy junior minister Nick Hurd.
Clark said the new facility was an "extraordinary achievement", and Hull was "setting the lead for the rest of the UK" in the clean power industry.
Also in attendance were representatives from Dong Energy and Statoil, Siemens' first customers at the site. The first batch of blades will be installed at Dong's 573MW Race Bank project, off the UK's east coast.
Statoil, meanwhile, will use the dock as the assembly base for its 402MW Dudgeon offshore project. The first towers for this project, also off the UK's east coast, are at the port.
The new facility currently employs 700 people, which is set to increase to 1,000 in 2017 as the ramp-up of activity hits its peak.