Mario Alberto Díaz (born 8 December 1999) is a Cuban discus thrower.

[2] He won a bronze medal at the 2022 NACAC Championships in Freeport, Bahamas in August 2022 with a 62.31 metres throw.

[3] He won gold at the 2023 Central American and Caribbean Games in San Salvador in July 2023 with a 62.57 metres throw.

[5][6] He finished fourth at the 2023 Pan American Games in Santiago.

[7] He competed in the discus throw at the 2024 Summer Olympics in Paris in August 2024.