Los Alvarez is a census-designated place (CDP) in Starr County, Texas, United States.

[16] Prior to the 2010 U.S. Census 4 CDPs (Barrera, El Quiote, Flor del Rio, and Palo Blanco) were carved out from its territory.

8.7% of all households were made up of individuals, and 4.2% had someone living alone who was 65 years of age or older.

Half of the current Los Alvarez CDP is in the Roma Independent School District, while the other half is in the Rio Grande City Grulla Independent School District (formerly the Rio Grande City Consolidated Independent School District).

[25] The eastern portion of the former CDP was served by the Rio Grande City Consolidated Independent School District.