Roberto R. Alonzo (born December 25, 1956) is a former Democratic member of the Texas House of Representatives, representing the 104th District from 1993 to 2019. Alonzo was defeated in the Democratic primary on March 6, 2018, by Jessica González.
Alonzo is an alumnus of The University of Texas at Austin and the Thurgood Marshall School of Law at Texas Southern University.
In 2017, during the 85th Texas Legislature, Representative Alonzo helped lead the fight against Senate Bill 4 by referencing the Chicano bogeyman known as "el cucuy". Rep. Alonzo's use of "el cucuy" attempted to communicate to his Republican colleagues the negative psychological effects legislation such as SB4 would have on immigrant communities.
Representative Alonzo drew the ire of some Dallas residents over a housing dispute. Alonzo ran for Texas Railroad Commissioner in 2020 triggering a runoff for the Democratic Party nomination with Chrysta Castañeda.