Dilley is a city in Frio County, Texas, United States. The population was 3,894 at the 2010 census. It is located off Interstate 35 south of the county seat in Pearsall.
Dilley is located in southern Frio County at 28°40′15″N 99°10′11″W (28.670824, -99.169820). Interstate 35 bypasses the city on the west, with access from Exits 82 through 86. I-35 leads northeast 71 miles (114 km) to San Antonio and south 83 miles (134 km) to Laredo. Pearsall, the county seat, is 16 miles (26 km) to the north. Texas State Highway 85 passes through the center of town as Leona Street, leading northeast 49 miles (79 km) to Pleasanton and west 58 miles (93 km) to Carrizo Springs.
According to the United States Census Bureau, Dilley has a total area of 2.4 square miles (6.1 km2), all of it land.
As of the census of 2000, there were 3,674 people, 955 households, and 727 families residing in the city. The population density was 1,574.3 people per square mile (608.8/km2).