RG1

RG1 may refer to:
 * Ginsenoside Rg1, a bioactive molecule
 * a United Kingdom postcode covering Reading area
 * RG-1 (propellant) is a 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