Yorkshire members voted overwhelmingly to buy Headingley with a £9m Leeds City Council loan at a meeting on Saturday.
Headingley has staged 65 Tests and 30 one-day internationals
All 206 present and 2,111 proxy voters - 98.37% of members - approved the buyout from Leeds Cricket, Football and Athletic Company, with 35 against.
Chief executive Colin Graves said the club would now try to push the £12m purchase through by 31 December.
That is the deadline for the club to own Headingley and keep its status as a venue for international matches.
Members also agreed the club should increase its borrowing powers to £25m to proceed with plans to redevelop the north-south grandstand and build a new pavilion and media centre at the Kirkstall Lane end.
Yorkshire must repay the Leeds City Council loan over a 15-year period and Graves told BBC Sport on Friday: "We're delighted to be able to secure the future of Test match cricket at Headingley.
"I'd like to thank Leeds City Council for everything its done for us, especially for giving us the chance to own this magnificent stadium."
Chairman Robin Smith added: "The arrangement represents a victory for the city and the club. The city's future and reputation will be enhanced by the continuity of international cricket at Headingley
"Without the council's loan, this transaction would have been impossible and now we can put in place a platform for enduring progress for the club and for Yorkshire cricket."
The news was welcomed by former Yorkshire captain Geoff Boycott, who famously scored his 100th century at the ground during the 1977 Ashes Test against Australia.
"Most people try to own their own house - you've got security then," he told BBC Five Live.
"They've built the East and West stands but there's still a lot of development needs to go on. They need a proper pavilion and something imposing and nice at Kirkstall Lane End that is aesthetic.
"Then, at some stage down the road, when they get themselves financially secure, they need to do something with the football stand - it's old, it's dilapidated and past its sell-by date."
Test cricket was first played at Headingley as long ago as 1899 and, although there was no Ashes Test there in the summer, it will return next August when England take on Pakistan.
But the addition of Durham's Riverside headquarters and the Rose Bowl in Southampton to the list of international venues means Yorkshire are not are guaranteed Test cricket every year.
The club has, however, been offered a staging agreement by the England and Wales Cricket Board, which guarantees Headingley's place on the list until 2019.
But they must own the ground by the end of 31 December for the agreement to come into effect.
Councillor Mark Harris, deputy leader of Leeds City Council, defended the outlay by saying: "We have always been very conscious of the importance of Test match status to Leeds.
"An independent study has shown that it would cost the city millions if Headingley lost it, not just in the present but in the future too.
"The cricket ground is one of the city's crown jewels and cricket one of its major sporting attractions. It is crucially important to the city's reputation and standing nationally and internationally.
"We are fully aware that these are public funds and throughout these negotiations it was vitally important that we were absolutely satisfied that the way in which we were lending the money was secure.
"The public can be assured that the loan will be at nil cost to the taxpayers, both the interest and the capital sum will be fully repaid by the club."