The Portuguese giants will be the seventh club of Duran’s career at the age of just 22, following recent stints with Fenerbahce and Zenit St Petersburg.
Benfica will pay a £5.19m (6.1m euros) loan fee for the Colombia international with the option to make the move permanent for £25.5m (30m euros) at the end of the 2026-27 season.
“I am happy! I continue to say that it is the biggest club in Portugal. I am very grateful to be here,” said Duran.
“I have very high expectations of being here. I want to play well, give my all and become champion.”
Duran began his professional career with Colombian side Envigado in 2019 before earning a move to MLS team Chicago Fire in 2022.
He was on the move again in January 2023 when he joined Aston Villa for £14m and quickly became a fan favourite.
A move to West Ham fell through in the summer of 2024, but after scoring a famous winner for Villa against Bayern Munich in the Champions League, Duran was sold to Al-Nassr for £71m in January 2025.