BRN is a three-letter acronym that may refer to:
- Board of Registered Nursing
- Barisan Revolusi Nasional, an insurgent movement in Southern Thailand
- Basic reproduction number, a measure of the speed in which an epidemic spreads
- Berne Airport, Switzerland, IATA airport code
- British Royal Navy, the navy of the United Kingdom of Great Britain and Northern Ireland
- Brunei Darussalam, ISO 3-letter country code
- Bulk Richardson number, meteorological number relating vertical stability and vertical shear
- Bunte Republik Neustadt, a district festival in Dresden-Neustadt
Usage examples of "brn".
Young mother, long blue gathered skirt, floral peasant blouse, dk brn hair in Indian braids, two kids, boy 4, girl 3, sloping grn meadow next to pond.