Dorchester is a city in Grayson County, Texas, United States. The population was 69 at the 2020 census, significantly down from 148 at the 2010 census. It is part of the Sherman–Denison Metropolitan Statistical Area.

Dorchester is located in southern Grayson County 13 miles (21 km) southwest of Sherman, the county seat, and 30 miles (48 km) north of McKinney.

According to the United States Census Bureau, Dorchester has a total area of 1.6 square miles (4.2 km), all land.

Historical population

Census	Pop.	Note	%±
1980	205		—
1990	137		−33.2%
2000	109		−20.4%
2010	148		35.8%
2020	69		−53.4%
U.S. Decennial Census 2020 Census

As of the census of 2000, there were 109 people, 43 households, and 31 families residing in the city. The population density was 108.9 inhabitants per square mile (42.0/km). There were 47 housing units at an average density of 47.0 per square mile (18.1/km). The racial makeup of the city was 92.66% White, 7.34% from other races. Hispanic or Latino of any race were 11.01% of the population.

There were 43 households, out of which 37.2% had children under the age of 18 living with them, 65.1% were married couples living together, 2.3% had a female householder with no husband present, and 27.9% were non-families. 27.9% of all households were made up of individuals, and 11.6% had someone living alone who was 65 years of age or older. The average household size was 2.53 and the average family size was 3.13.

In the city, the population was spread out, with 31.2% under the age of 18, 5.5% from 18 to 24, 32.1% from 25 to 44, 22.0% from 45 to 64, and 9.2% who were 65 years of age or older. The median age was 34 years. For every 100 females, there were 94.6 males. For every 100 females age 18 and over, there were 102.7 males.

The median income for a household in the city was $45,000, and the median income for a family was $67,083. Males had a median income of $42,000 versus $26,750 for females. The per capita income for the city was $16,947. There were 9.7% of families and 7.9% of the population living below the poverty line, including 10.6% of under eighteens and none of those over 64.

Until 1959, Dorchester had its own school, originally built in 1902 (a state historical marker stands at the school's old location, next to the current home of the First Baptist Church of Dorchester). The high school closed in 1940, but the elementary school remained for nearly 20 more years, when the Dorchester school merged with the Howe Independent School District. The Howe district continues to educate students in the area today. The Dorchester Dragon's School Song was originally written by Emily Juanita Stewart. She currently resides in Howe, Texas. Russell Wortham of Howe is the last known recipient of the coveted "Dorchester Dragon Spirit Award" which was presented in 2010. This award was presented to:

The Howe High School student who displayed the highest level of "Dragon Spirit" amongst the students enrolled in the Dorchester and Howe areas.