The projects have gone to developers Smart Wind and Mainstream. Mainstream has secured the lease for the 450MW Neart na Gaoithe project in the Forth estuary, Scotland.
Smart Wind, which is a joint venture with Mainstream and Siemens, has won two projects (Heron Wind and Njord) totalling 1GW in the Hornsea zone off England's north-east coast.
Construction on all three projects is set for 2014.
Speaking about the deals, Mainstream chief executive Eddie O'Connor said: "Mainstream is following a strategic risk diversification policy of investing in both onshore and offshore wind as well as solar.
"The profound electricity future for Europe is about offshore wind, in which Mainstream has established a pre-eminent position," he added. "In addition to a very large near-term build programme onshore across a number of jurisdictions, Mainstream is delighted to report on this progress of our offshore endeavours."
Speaking about the award of the two Hornsea projects, Andy Kinsella, CEO of Mainstream's offshore business and chairman of Smart Wind, commented: "This is another major step forward for Smart Wind. We recently announced the signing of a £60 million framework agreement with Fugro to carry out detailed Geotechnical studies.
"We're now firmly focused on bringing these project through the consent process and into construction on time so that we can start benefitting from this indigenous and free-fuel source of power."