Royse City is a city in Rockwall County in the U.S. state of Texas. It also extends into Collin and Hunt counties. The population was 2,957 at the 2000 census, rising to 9,349 in 2010. The estimated population in 2018 was 12,998. In 2020, its population grew to 13,508.

Collin County is located in the U.S. state of Texas. It is part of the Dallas-Fort Worth-Arlington metropolitan statistical area, and a small portion of the city of Dallas is in the county. At the 2020 United States census, the county's population is 1,064,465, making it the sixth-most populous county in Texas and the 43rd-largest county by population in the United States. Its county seat is McKinney.