R99

R99 may refer to:
 * R99 (New York City Subway car)
 * R99 (star)
 * Embraer R-99, a Brazilian Air Force military aircraft
 * Hydrotreated vegetable oil, a sustainable fuel
 * HMS Urchin (R99), a destroyer of the Royal Navy
 * FRENCH AIRCRAFT CARRIER Foch
 * R99, a NIOSH air filtration rating for respirators