Rb or RB may stand for:
RBW (Hangul:알비더블유; an acronym for Rainbow Bridge World) is a South Korean entertainment company founded by Kim Jin-woo (Hangul: 김진우) and Kim Do-hoon (Hangul: 김도훈) The label is home to artists such as Mamamoo, Vromance, Jin-Ju, ONEWE and ONEUS.
RBT is an Australian factual television series that looks at the everyday workings of sobriety check points by Random Breath Testing (or RBT) police units, and is narrated by Australian actor Andrew Daddo.
The RBS-15 (Robotsystem 15) is a long-range fire-and-forget surface-to-surface and air-to-surface, anti-ship missile.