The trio were the last three standing following a vote by a jury comprising the coaches of the 80 clubs from last season's Champions League and Europa League, as well as 55 journalists representing UEFA's member associations.
"Players are judged on their performances in all competitions - domestic, continental and global", UEFA said in a statement. Modric won the Golden Ball as the World Cup's best player in Russian Federation.
Modrić was even awarded with the Golden Ball in recognition for his performances at the World Cup, a trophy last has previously been one by the likes of Lionel Messi, Ronaldo Nazário and the late Johan Cruyff.
The award, which rivals the Ballon d'Or is run by UEFA and perhaps there in lies the reason for Ronaldo's preference over Messi.
The victor will be announced August 30 at the 2018-19 Champions League group stage draw. Ronaldo's assist record was far worst though, with just fife in La Liga and three in the Champions League, although the Portuguese forward would often lead the attack for Madrid. He has also won the award on three occasions compared to Messi's two.
Ronaldo had a mixed campaign by his own high standards last term, despite finishing top of the Champions League scoring charts with 15 goals.
Uefa also revealed the nominees for team of the year, with Alisson Becker, Gianluigi Buffon and Keylor Navas between the sticks.
Griezmann is on a three-player list to be named the best Europa League player last season, after scoring twice in Atletico's 3-0 win over Marseille in the final.
UEFA will also announce the women's player of the year from a shortlist of Pernille Harder (Denmark and Wolfsburg), Ada Hegerberg (Norway and Lyon), and Amandine Henry (France and Lyon).