According to the census2 of 2000, there were 110,595 people, 42,849 households, and 30,208 families residing in the county. The population density was 46/km² (118/mi²). There were 48,315 housing units at an average density of 20/km² (52/mi²). The racial makeup of the county was 87.20% White, 5.85% Black or African American, 1.31% Native American, 0.57% Asian, 0.05% Pacific Islander, 2.90% from other races, and 2.13% from two or more races. 6.80% of the population were Hispanic or Latino of any race.

There were 42,849 households out of which 32.10% had children under the age of 18 living with them, 55.20% were married couples living together, 11.40% had a female householder with no husband present, and 29.50% were non-families. 25.50% of all households were made up of individuals and 11.40% had someone living alone who was 65 years of age or older. The average household size was 2.51 and the average family size was 3.00.

The median income for a household in the county was $37,178, and the median income for a family was $45,048. Males had a median income of $32,998 versus $23,414 for females. The per capita income for the county was $18,862. 11.30% of the population and 8.40% of families were below the poverty line. 13.80% of those under the age of 18 and 10.10% of those 65 and older were living below the poverty line.

Neighboring areas include Marshall County, Okla., Bryan County, Okla., Fannin County, Collin County, Denton County, Cooke County, and Love County, Okla. Cities and towns are Bells, Collinsville, Denison, Dorchester, Gordonville, Gunter, Howe, Knollwood, Pottsboro, Sadler, Sherman, Southmayd, Tioga, Tom Bean, Van Alstyne, and Whitesboro.