, better known as Marquinhos (Brazilian Portuguese: [maʁˈkĩɲus]), is a Brazilian professional footballer who plays as a centre-back and captains both Ligue 1 club Paris Saint-Germain and the Brazil national team. He is considered one of the best centre-backs in the world.

Marquinhos began his career at Corinthians, and after winning the 2012 Copa Libertadores he moved to Roma for an eventual fee of €3 million. He was a regular in his only season as Roma reached the Coppa Italia final. In July 2013, he moved to PSG for €31.4 million, one of the highest fees for a player under the age of 20. Marquinhos played less frequently after the acquisition of compatriot David Luiz in 2014, returning to an integral role after the latter was sold in 2016. He was part of PSG's team that reached the 2020 UEFA Champions League final. After Thiago Silva's departure in August 2020, he took up the role of captain. In 2025, he captained PSG to their first ever Champions League title, beating Inter with a record margin of 5–0 to complete a continental treble. In total with PSG, Marquinhos has won a record 10 Ligue 1 titles, 14 domestic cups, and one Champions League title. He ranks top for all-time appearances for the club, with over 450.

Marquinhos made his full international debut for Brazil in 2013, and was part of their under-21 side which won the 2014 Toulon Tournament. He also represented the nation at the 2015 Copa América and the following year's Copa América Centenario, and won a gold medal at the 2016 Olympics. He subsequently took part in two FIFA World Cups (2018 and 2022) and three additional Copas América (2019, 2021 and 2024), winning the 2019 title.