Luis César Alvarado Martínez (January 15, 1949 – March 20, 2001) was a Puerto Rican infielder in Major League Baseball (MLB).

In 1969 he started at Triple-A with the Louisville Colonels, and led the International League in runs (89) and hits (166), garnering Most Valuable Player honors.

After hitting .224 in 59 games for Boston in 1970, he was traded along with Mike Andrews to the Chicago White Sox for Luis Aparicio on December 1 of that year.

He played in parts of 1974 to 1977 divided between the Cardinals, Indians, Mets and Tigers and for several teams in the Mexican League from 1979 to 1981.

Alvarado died in his hometown of Lajas, Puerto Rico, at the age of 52 from a heart attack on March 20, 2001.