Casemiro or Carlos Henrique Casimiro (born 23 February 1992), known as Casemiro, is a Brazilian professional footballer who plays as a defensive midfielder for Premier League club Manchester United and the Brazil national team. Known for his tackling, positioning and excellent reading of the game, Casemiro is regarded as one of the best defensive midfielders in the world and of his generation.

Formed at São Paulo, where Casemiro scored 11 goals in 111 official games, Casemiro moved to Real Madrid in 2013, and also spent 2014–15 on loan at Porto. Casemiro was part of the Real Madrid squad that won four Champions League titles in five seasons, from 2014 to 2018. In total Casemiro won fifteen major trophies at Real Madrid, including five Champions Leagues, three La Liga titles, one Copa del Rey and three FIFA Club World Cups. In 2022, Casemiro moved to Manchester United in England.

A full international since 2011, Casemiro was in Brazil's squad at the 2018 FIFA World Cup as well as four Copa América tournaments, winning the 2019 edition.