Olmito is a census-designated place (CDP) in Cameron County, Texas, United States.

Route 83 runs along the eastern side of the community, leading northwestward 10 miles (16 km) to San Benito and south 9 miles (14 km) to Brownsville.

[4] Olmito Lake is in the northern part of the town, and the Resaca del Rancho Viejo, an ancient channel of the Rio Grande, forms the western edge of the community.

9.9% of all households were made up of individuals, and 5.3% had someone living alone who was 65 years of age or older.

Olmito is served by the Los Fresnos Consolidated Independent School District.

The United States Postal Service operates the Olmito Post Office.

[22] The climate in this area is characterized by hot, humid summers and generally mild to cool winters.