Ramón Ángel Díaz (born 29 August 1959) is a former Argentine footballer and manager. He played for River Plate as a striker, and coached it for three tenures, winning eight titles. He is also known by the nickname of El Pelado ("Baldy").
Díaz was born in the city of La Rioja in the province of the same name. He played as a forward and starred in River Plate's youth system under Norberto "El Pacha" Yacono. His opening game in the Argentine First Division was on 13 August 1978, a game where River Plate beat Colón de Santa Fe by 1–0. He scored his first goal on 30 August of that year, playing against Quilmes Atlético Club. Diaz went on to feature for clubs such as River Plate, Inter Milan, Yokohama Marinos, and Monaco under famed manager Arsene Wenger.
Diaz won the World Youth Cup in 1979 with the Argentina under-20 team alongside Diego Maradona, winning the golden boot for being the topscorer of the competition. He then went on to play in the 1982 FIFA World Cup and scored against Brazil in Argentina's 3–1 defeat. It had been rumoured that he and Maradona were involved in a feud which prevented Diaz from playing for Argentina in the 1986 and 1990 World Cups. However, this was denied by Maradona in his autobiography Yo soy el Diego, claiming that he had told the then-Argentina manager, Carlos Bilardo, that he wanted Diaz in both the 1986 and 1990 World Cup squads.