RGN or Rgn may refer to:

• RGN, a human gene which codes for the protein regucalcin
• RGN hand grenade, a Soviet weapon
• Registered general nurse, in the United Kingdom
• rgn, ISO 639-3 language code for the Romagnol language
• RGN, IATA code for Yangon International Airport in Myanmar

• 4.38x30mm Libra
• 4.38×30 mm Libra
• (43900) 1995 VH2
• (43905) 1995 WC1
• (43909) 1995 WB9
• (43920) 1996 CJ2
• (43952) 1997 BG7
• (43959) 1997 CB26
• (43964) 1997 EF23
• 4397th Air Refueling Training Wing
• 4397th Air Refueling Wing
• (43982) 1997 GA32
• 4399
• 4:39 AM (For the First Time Today, Part 2)
• 439 in poetry
• 439 (MBTA bus)
• 439 (RCAF) Sqn
• 439 (Sabre-Toothed Tiger) Squadron CAF
• 439 Sqn RCAF
• 439 Squadron CAF
• 439th Fighter-Bomber Group
• 439th Light Anti-Aircraft Regiment, Royal Artillery
• 439th Military Airlift Group
• 439th (Tyne) Light Air Defence Regiment, Royal Artillery
• 439 U.S. 1105