Bruin
- County:
- Butler County
- County Seat:
- No
- Area (mi²):
- 1.825
- State:
- Pennsylvania
Bruin is a borough located in Butler County, Pennsylvania. Bruin has a 2026 population of 402. Bruin is currently declining at a rate of -0.74% annually and its population has decreased by -4.06% since the most recent census, which recorded a population of 419 in 2020.
The median household income in Bruin is $67,031 with a poverty rate of 2.54%. The median age in Bruin is 52 years: 49.7 years for males, and 53.2 years for females. For every 100 females there are 93.4 males.