This paper reveals the impact of voter turnout on the legitimacy of presidential elections based on the materials of 20 largest states holding such elections in terms of the number of voters. In March 2024, presidential elections were held in Russia and in November elections are scheduled in the United States, the outcome of which will have an impact on the domestic and foreign policies of these states. The author has tested the hypothesis that in most cases, for the existing political regime in countries where subject and patriarchal political cultures are widespread, high voter turnout acts as a donor of legitimacy, therefore, the authorities seek to involve the maximum number of voters in conventional political participation in presidential elections and ensure victory for the person holding the offi ce of president (incumbent). In countries where the political culture of participation has become more widespread, the competition of strong candidates is a source of legitimacy for political regimes that do not seek to mobilize all voters to participate in presidential elections and are most often unable to ensure the re-election of the incumbent. Based on the analysis of electoral statistics of presidential elections in the studied states, it was concluded that high electoral activity in countries with a predominance of national and patriarchal political cultures, even if there is no real competition between candidates, but with broad public recognition of the existing political regime, ensures the legitimacy of elections. In countries where political culture of participation has become more widespread, high turnout is a consequence of interest in elections, and not the result of the mobilization of the electorate by the political regime. Examples are Turkey and France, where the last presidential elections were held with high turnout and competition between the two most popular candidates; low electoral activity in the presidential elections is a prerequisite for the subsequent political crisis and dismantling of the political regime (Afghanistan, Nigeria). Acceptable level of voter turnout in the presidential elections, which can act as an indicator of their legitimacy, is about 60–66%.