The figure was an increase from 9.5% in 2014. The UK's turbines also broke weekly, monthly and quarterly generation records, said trade body RenewableUK.
In October to December 2015, 13% of the country's electricity demand was supplied by wind, beating a previous record of 12% in the first quarter of 2015.
A new weekly record was set in the last full week of December, with 20% of needs met by wind.
And December was also the windiest month, with 17% of demand met by wind, beating the record set in January 2015.
RenewableUK director of policy Gordon Edge said: "We can continue to increase the proportion of the nation's electricity which we provide as we move away from fossil fuels to clean sources of power."
RenewableUK figures show new onshore capacity totalled 402.7MW in 2015, with an additional 1.1GW added offshore.