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

It is a new CDP formed from part of the Garceno CDP prior to the 2010 census, with a population of 129.

[2] San Juan first appeared in the 2010 U.S. Census after being carved out from part of the Garceno CDP.

[15] The CDP is within the Roma Independent School District.

[19] Roma High School is the district's sole comprehensive high school.