According to the 2010 census, Wrentham has a population of 10,955. It is 49.3% male and 50.7% female.
The town is lacking in racial diversity, clocking in at 97.1% white, .6% black, .2% American Indian/Alaskan Native, 1% Asian, 0% Pacific Islander, .2% from another race, and 1% from two or more races. 1.2% of Wrentham is Hispanic or Latino.