Luis Héctor Cristaldo Ruiz Díaz (born August 31, 1969, in Formosa, Argentina) is an Argentine-born Bolivian football midfielder.

He is Bolivia's national team record cap holder alongside Marco Sandy.

Born in Argentina, he relocated to Santa Cruz, Bolivia at the age of 15. Cristaldo then began attending the prestigious Tahuichi football academy, and by the time he was 18 years old he made his official debut in first division. He played for Bolivian teams Oriente Petrolero (1990–92) and Bolívar (1993–98), winning 4 national titles combined during those years.

In 1998, he went abroad to play for Sporting de Gijón in Spain and later with Cerro Porteño and Sol de América in Paraguay, not to mention a previous spell he had during 1994 with Argentine club Mandiyú de Corrientes and legendary Diego Maradona as the manager.

In 2001, Cristaldo returned to Bolivia and played with The Strongest for the next six years. In 2007, during his second spell with Oriente Petrolero he called it quits, laying his football career to rest permanently after seventeen years of professional football.

Cristaldo played at the 1987 FIFA U-16 World Championship in Canada.^[1]

He and Marco Sandy hold the record for the most appearances for the Bolivia national team with 93 international matches and 5 goals between 1989 and 2005, including two appearances in the 1994 FIFA World Cup.^[2] Cristaldo made his international debut on September 10, 1989, in a World Cup Qualifier against Uruguay in Montevideo (2-0 loss) and equalled Sandy's record in his final match against Brazil in October 2005. He represented his country in 33 FIFA World Cup qualification matches and at the 1999 FIFA Confederations Cup.^[1]