Breen is an unincorporated community on the Southern Ute Indian Reservation in La Plata County, Colorado, United States.
The Southern Ute Indian Reservation was created on November 9, 1878. The Breen, Colorado, post office operated from July 19, 1901, until November 30, 1954. The community was named after Dr. Thomas Breen, a local educator.
Breen is located at coordinates .