RPN
RPN may refer to:
Science and technology
- Real projective space (), a type of topological space
 - Reverse Polish notation, a.k.a. postfix notation, a mathematical notation
 - Registered Parameter Number, in MIDI
 - Recherche en Prévision Numérique, weather forecasting research service, Canada
 - Risk priority number in failure analysis such as FMEA, taking into account the severity, probability and detection probability of a failure event
 
Nursing
- Registered practical nurse, nursing title
 - Registered psychiatric nurse, nursing title specialising mental health
 
Other uses
- Radio Philippines Network, Channel 9
 - Rosh Pina Airport (IATA code), Israel
 - Rancangan Perumahan Negara (National Housing Programme), public housing in Brunei