RG1
RG1 may refer to:
- Ginsenoside Rg1, a bioactive molecule
 - a United Kingdom postcode covering Reading area
 - RG-1 (propellant) is a Soviet/Russian rocket propellant similar to RP-1
 - R1–RG1 (Rodalies de Catalunya), a commuter rail line in Catalonia, Spain
 
RG-I may refer to:
- Rhamnogalacturonan I, a type of pectin