Krejčikova and Sinijakova defeated American Bethany Matek Sands and Polish Iga Švjontek in the final with 6: 4, 6: 2, after an hour and 16 minutes of play.
Barbora Krejčikova won the individual competition title at Roland Garros yesterday.
She thus became the first tennis player to win trophies in both singles and doubles in Paris since Mary Pierce, who succeeded in 2000.
Krejčikova and Sinijakova won their second joint title at Roland Garros after lifting the 2018 trophy. They also won Wimbledon that year.