It follows a £15million agreement - subject to the approval of the club's members - with Leeds Cricket Football and Athletic Company Limited (LCF&A).
The deal would see the club purchase the cricket ground freehold and, with it, the income from catering, drinking, advertising and the hotel (around £900,000 per annum in a Test match year).
The price is £12m, plus £3m to be paid at any time within 15 years. Most of the funding of the purchase price is via a loan from Leeds City Council.
The deal will also allow the ground to stage Test matches until 2019 as part of its staging agreement with the England and Wales Cricket Board.
Discussions have also begun with LCF&A, Yorkshire Forward and Sport England over plans to replace the joint cricket/rugby stand, and to build a new pavilion and media centre on Kirkstall Lane.
Chairman Robin Smith said at Headingley this morning: "This is the greatest day in the history of Yorkshire County Cricket Club. It is an excellent day for Yorkshire cricket, an excellent day for rugby, for the people of Leeds, and for the cricket-loving public of Yorkshire and beyond."
Marketing director Ian Bishop said: "This now gives us freedom to do a number of commercial deals that in the past we've been unable to do."
