According to the census2 of 2000, there were 36,210 people, 10,850 households, and 8,137 families residing in the county. The population density was 12/km² (31/mi²). There were 12,294 housing units at an average density of 4/km² (11/mi²). The racial makeup of the county was 66.08% White, 14.75% Black or African American, 0.80% Native American, 0.45% Asian, 0.03% Pacific Islander, 14.67% from other races, and 3.22% from two or more races. 39.59% of the population were Hispanic or Latino of any race.

The median income for a household in the county was $33,592, and the median income for a family was $34,902. Males had a median income of $25,896 versus $20,070 for females. The per capita income for the county was $13,663. 24.10% of the population and 16.90% of families were below the poverty line. 29.90% of those under the age of 18 and 15.00% of those 65 and older were living below the poverty line.

Neighboring areas include the following: Glades County, Palm Beach County, Broward County, Collier County, Lee County, and Charlotte County. The cities and towns of Hendry County are Clewiston, Harlem, LaBelle, Port LaBelle, and Felda.