As a three letter acronym, RBK may refer to:
- Reebok, a company specializing in sportswear and goods, or a brand of sportswear made by Reebok.
- Rosenborg BK (Rosenborg Ballklub), a Norwegian football club
- Royal Borough of Kingston upon Thames, in Greater London
- Rögle BK (Rögle Bandyklubb), an ice hockey club from Sweden
- Rheinisch-Bergischer Kreis, a district of North Rhine-Westphalia in Germany
- Common Russian abbreviation for RBC Information Systems and RBC TV, its TV channel
- IATA airport code for French Valley Airport.