RMG could apply to any of the following:
- RMG Connect, the marketing division of JWT, the fourth-largest advertising agency in the United States
- RCA Music Group, an umbrella group of labels that was merged with RCA Records
- Rail Mounted Gantry, a type of industrial crane
- RPG-28, a Russian rocket launcher known as RMG
- Rover's Morning Glory, a syndicated morning radio talk-show broadcast from WMMS in Cleveland, Ohio
- Revolutionary Marxist Group (Canada), a Trotskyist political organization in Canada in the 1970s