Diego Basilio León Blanco (ডিয়েগো বাসিলিও লিওন ব্লাঙ্কো) is a Paraguayan professional footballer who plays as a left-back and left wing-back for Premier League club Manchester United.

León was born on 3 April 2007 in Colonia Yguazú, Paraguay, as the youngest of nine children. He is the son of Brígida Blanco.

León began his career with Cerro Porteño, making his senior debut on 2 August 2024, in a 1–0 win over Sportivo Ameliano, scoring the winning goal.

It was announced on 11 January 2025 that León would sign for Premier League club Manchester United in the summer window. On 5 July 2025, Manchester United confirmed the signing of León.

He has been described as "one of the great promises of Paraguayan football".