Adjarabet is licensed to offer a full suite of online betting and gaming products, which includes casino, sports and poker, within Georgia.
Paddy Power Betfair now has a 51% stake in the Georgian company, which cost £101m ($131.9m).
Plans are in place to purchase the remaining 49% after three years, at a price equivalent to seven times Adjarabet’s 2021 EBITDA underlying earnings.
Adjarabet generated revenue of £64m in 2018 and EBITDA of £20m.
Peter Jackson, Paddy Power Betfair CEO, said: "This bolt-on acquisition is in line with our strategy of establishing podium positions in attractive online markets.
"Adjarabet’s leading brand presence and strong management team has established it as the clear number one in the fast-growing, regulated online Georgian market.
"Together with our group’s technology and sports capabilities, we are confident Adjarabet will be strongly positioned to build on this success."