RPN is an acronym that may refer to:
- Registered Practical Nurse, also referred to as a licensed practical nurse
- Radio Philippines Network, Channel 9, Philippines
- Registered Parameter Number, as used in Musical Instrument Digital Interface synthesizers
- Registered Psychiatric Nurse
- Reverse Polish notation, a.k.a. Postfix notation, a mathematical notation
- Risk Priority Number, as used in failure mode and effects analysis
- Recherche en Prévision Numérique, a numerical weather prediction research center in Canada
RPN may also refer to:
- RPN, the IATA airport code for Rosh Pina Airport, Israel
- RPn, Real projective space, in mathematics