Mark W. Stiles Unit is a Texas Department of Criminal Justice men's prison located in an unincorporated area of Jefferson County, Texas,[1] near Beaumont.

The unit, located along Farm to Market Road 3514, is 4 miles (6.4 km) southeast of downtown Beaumont.

The unit serves as the University of Texas Medical Branch hub site for treatment of HIV and other infectious diseases.

[2] As a result, the Stiles facility houses many HIV positive prisoners.

[3] A hospice for prisoners with HIV opened at Stiles in 1997.