Rubén Darío Amorín Mattos (6 November 1927 – 24 December 2014) was an Uruguayan football player and coach. He was born in Montevideo.
Amorín arrived in 1952 in Guatemala to play for Guatemala FC.
He has spent the majority of his coaching career in Guatemala, where he won a record eight national titles with three different clubs from 1964 to 1992, and took Municipal to win the CONCACAF championship in 1974, the only time a Guatemalan club has won that title.
He also had five different tenures as coach of the Guatemala national team, winning the 1967 NORCECA Championship (now the CONCACAF Gold Cup) which is the highest international honor for that national team to date. He retired in 1994.
Due to his success at both the club and international level, Amorín has been catalogued as the greatest coach in the history of Guatemalan football by the local press and by many observers. On 24 December 2014, he died of Alzheimer's disease at the age of 87.