Holec enjoyed his first inclusion in the wider squad of Slovak senior
national team in November 2019, when he was listed as an alternate by
Pavel Hapal for two qualifying
UEFA Euro 2020 qualifying fixtures against
Croatia and
Azerbaijan. After
Dominik Greif was ruled out of the match due to health issues, Holec joined the squad ahead of the Azerbaijan fixture. Holec was also additionally called up in September 2021, when
Dušan Kuciak tested positive for
COVID-19, but again failed to make an appearance. In March 2022, Holec was nominated for two friendly fixtures against
Norway and
Finland. He did not make an appearance on 25 March 2022 in
Oslo fixture against
Norway, which concluded in a 2-0 defeat, following strikes by
Erling Haaland and
Martin Ødegaard. Days later, Holec appeared in the starting line-up in the subsequent match, debuting on 29 March 2022, in a
neutral field international friendly against Finland. Following an agreement with goalkeeper's coach
Miroslav Seman, Holec and a fellow debutant,
František Plach were to both feature for one half of the game. During the first half, Holec faced two shots from the opposing team. The match concluded in a 2-0 victory, after a first-half strike by
Ondrej Duda and a second-half securing goal by
Erik Jirka. Following the match, Holec and Plach both praised the defensive line commanded by
Milan Škriniar, expressed pride over representing their nation and claimed that lack of spectators was the only regret related to their debut. ==Personal life==