Thunderbird Bay is a census-designated place (CDP) in Brown County in central Texas, United States.

[3] Thunderbird Bay is located in north-central Brown County along the northern arm of Lake Brownwood, a reservoir on Pecan Bayou.

By road, the CDP is 20 miles (32 km) north of Brownwood, the county seat.

[3] Thunderbird Bay first appeared as a census designated place in the 2010 U.S.

[16] As of the 2020 United States census, there were 764 people, 357 households, and 141 families residing in the CDP.