RPN

RPN may refer to:

Science and technology

 * Real projective space ($$\mathbb{R}\mathrm{P}^n,$$), 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