Alex Telles was born on 15 December 1992 in Caxias do Sul, in the southern Brazilian state of Rio Grande do Sul. He came through the youth setup at Esporte Clube Juventude before making his professional debut for them in January 2011. A move to Grêmio followed in late 2012, and by the end of the 2013 Série A season he had been named the league's best left-back, earning the Bola de Prata award in that position.
From Brazil, Telles moved to Galatasaray in January 2014, winning a Süper Lig title, two Turkish Cups and the Turkish Super Cup before a loan spell at Inter Milan in 2015–16. His career took a significant step forward when FC Porto signed him in July 2016 for €6.5 million. Over nearly four seasons he made close to 200 appearances, claimed two Primeira Liga titles, a Taça de Portugal and a Supertaça, and was named in the Primeira Liga Team of the Year for three consecutive seasons.
In October 2020, Manchester United paid around £15.4 million to bring him to Old Trafford. His time there included a memorable Champions League volley against Villarreal in September 2021. A loan to Sevilla in 2022–23 brought a UEFA Europa League winners' medal, and a subsequent move to Al-Nassr was followed by a return to Brazil with Botafogo in September 2024, where he scored in the Copa Libertadores final to help the club win the trophy.
An attacking left-back with good delivery and a sharp eye for goal, Telles earned his first senior Brazil cap in March 2019 and was part of the 2022 FIFA World Cup squad. He now brings that experience to Botafogo on a contract running to the end of 2026.