The Department of Energy and Climate Change (DECC) said the government will introduce primary legislation to close the RO.
About 5.2GW of projects already planned may be eligible for a grace period.
It is however estimated that about 3,000 wind turbines are awaiting planning permission and an early end to the subsidies may result in cancellation of those projects.
UK Energy and Climate Change Secretary Amber Rudd said: "Onshore wind is an important part of our energy mix and we now have enough subsidised projects in the pipeline to meet our renewable energy commitments.
"We want to help technologies stand on their own two feet, not encourage a reliance on public subsidies."
In 2014, onshore wind generated 5% of the UK’s electricity with the help of more than £800m of government subsidies.
DECC said it will consider options to continue support for community energy projects, as part of the Feed-in Tariff review later in 2015.
RenewableUK, the trade association for the wind industry, has urged the government to reconsider onshore wind cuts.
RenewableUK chief executive Maria McCaffery said: "The Government’s decision to end prematurely financial support for onshore wind sends a chilling signal not just to the renewable energy industry, but to all investors right across the UK’s infrastructure sectors."
Scottish Renewables said the closing of the RO a year earlier than planned is bad for jobs, bad for investment and can only hinder Scotland and the UK’s efforts to meet binding climate change targets.
Scottish Renewables chief executive Niall Stuart said: "Scottish Renewables completely rejects the UK Government’s rationale for cutting support for onshore wind.
"We believe this decision could put around two gigawatts of onshore wind projects in Scotland at risk. These are projects that could provide the equivalent electricity demand of 1.23 million Scottish homes and significantly improve our energy security, while bringing around £3 billion pounds of investment."
Image: UK to end the Renewables Obligation subsidy regime for new onshore wind farms. Photo: courtesy of pakorn/FreeDigitalPhotos.net.
