RDG may refer to:

Rail Delivery Group, a body in the privatised British railway system

Royal Dragoon Guards, the Royal Dragoon Guards is an armoured regiment of the British Army

Reading Company, a railroad that operated in southeast Pennsylvania and neighboring states in the United States

Reading railway station, National Rail station code RDG

University of Reading, a university in the English town of Reading, Berkshire

Reading Regional Airport in Reading, Pennsylvania, IATA Airport Code "RDG"

Rosetta Design Group, a CRO in the United States

Rwanda Development Gateway, a project to set up a national Rwandan portal for information sharing

RDG Red Data Girl, fantasy novel series by Noriko Ogiwara

Revolutionary Democratic Group, socialist organisation in the United Kingdom

In the field of temperature measurement it stands for "reading"

Rechtsdienstleistungsgesetz, the German Legal Services Act