Thomasville is a census-designated place in northern Oregon County, Missouri, United States. It is located 9 miles (14 km) northwest of Alton on Route 99.

According to a 1945 thesis on southern Missouri place names, the community was named for George Thomas, a pioneer settler, in 1817. However, in 1961, the State Historical Society of Missouri placed a historical plaque that claims the town was named after land donors, John and Matilda Thomas, in 1845.

The first settlers in the area arrived in the mid-1810s from Kentucky, settling in several log cabins along the Eleven Point River. The colony steadily grew over the next few decades. A Baptist church was established the 1830s.

When Oregon County was established in 1841, Thomasville was elected its first county seat, which at that time included parts of modern-day Howell, Shannon, and Carter Counties. The county seat moved to nearby Alton in 1859. Thomasville was platted in 1846. A post office called Thomasville was established in 1846 and remained in operation until 1979.

Historical population

Census	Pop.	Note	%±
2010	68		—
2020	23		−66.2%
U.S. Decennial Census

As of the 2020 US Census, there were 23 people, 15 households, and ? families living in the census-designated place. The population density was ? inhabitants per square mile. The racial makeup of the city was 82.6% White, 4.3% Black or African American, and 13% two or more races (White and Native American).

There were 15 households, of which 13% had children under the age of 18 living with them, 80% were married couples living together, 13.3% had a female householder with no spouse or partner present, and 6.7% had a male householder with no spouse or partner present. 86.7% had someone living there who was 65 years of age or older. 80% lived in owned properties while 20% rented. The median age was 56.5 years: 45.9 for males and 65.5 for females. 17.4% of residents were under the age of 18 and 26.1% were 65 years of age or older. The gender makeup of the city was 47.1% male and 52.9% female.

Thomasville has a public library, the Thomasville Branch library.