The debut for Czech Republic came on 15 November 2013 in Olomouc in the friendly against Canada. Ondra scored his first goal in the third minute. The coach Josef Pešice used Ondra for all 90 minutes of the game.
His second cap was won on 22 March 2017 when Ondrej played against Lithuania in a friendly in Ústí nad Labem. He assisted the third goal in a 3-0 win.
The third cap for Ondrej came in a friendly against Belgium on 5 June 2017.
The fourt cap for Ondrej was won in a friendly v Iceland (2-1) played on 8 November 2017 in Qatar.
The first cap in a competitive match was won on 13 October 2018 in UEFA Nations League against Slovakia. The eight and ninth in UEFA EURO qualifier vs England at Wembley and friendly vs Brazil in Prague. The tenth in the home game vs Bulgaria at Letná on 7 June 2019.