Denil Daniel Castillo Preciado (born 24 March 2004) is an Ecuadorian professional footballer who plays as a midfielder for FC Midtjylland and the Ecuador national team.
On 24 April 2023, Shakhtar Donetsk announced that they'd signed Castillo to a five-year contract from Liga de Quito, commencing 1 July 2023.
Castillo signed a five-year deal with Danish Superliga side FC Midtjylland for a â¬4 million transfer fee on 1 July 2024. In March 2026 he extended his contract with Midtjylland until 2031.
Castillo has represented Ecuador at youth level.
Castillo mainly operates as a central midfielder.