Rhea Mills is an unincorporated farming community in Collin County, Texas, United States.

A post office was established at Rhea Mills in 1876 and remained in operation until 1907 when mail was rerouted from McKinney.

It has served as a trade and supply center for local farmers for most of its existence.

[3] Rhea Mills is located at the intersection of Farm to Market Roads 2478 and 1461, 6 mi (9.7 km) northwest of McKinney in northwestern Collin County.

[2] Today the community is served by the Prosper Independent School District.