The move follows the closure of the airport in 2022 after owners Peel Group claimed it was no longer financially viable following the departure of Wizz Air, leaving Tui the only regular customer.
South Yorkshire Mayoral Combined Authority has agreed the funds to help build a case for a Compulsory Purchase Order (CPO) currently being undertaken by City of Doncaster Council.
South Yorkshire and four other councils also agreed an undisclosed funding package towards the purchase of the airport, should the CPO succeed.