Royal institute
- Chatham House
- Grand Ducal Institute
- KNMI (institute)
- Liverpool Royal Institution
- Royal Anthropological Institute of Great Britain and Ireland
- Royal Archaeological Institute
- Royal Architectural Institute of Canada
- Royal Australian Chemical Institute
- Royal Australian Institute of Architects
- Royal Australian Institute of Architects Gold Medal
- Royal Belfast Academical Institution
- Royal Belgian Institute of Natural Sciences
- Royal Black Institution
- Royal Canadian Institute
- Royal Cork Institution
- Royal Institute for Deaf and Blind Children
- Royal Institute of British Architects
- Royal Institute of Chemistry
- Royal Institute of Navigation
- Royal Institute of Oil Painters
- Royal Institute of Painters in Water Colours
- Royal Institute of Philosophy
- Royal Institute of Technology
- Royal Institute of Thailand
- Royal Institute of the Amazigh Culture
- Royal Institute of the Architects of Ireland
- Royal Institution
- Royal Institution of Chartered Surveyors
- Royal National Institute for Deaf People
- Royal National Institute of Blind People
- Royal National Lifeboat Institution
- Royal New Zealand Institute of Horticulture
- Royal Scottish Academy
- Royal Town Planning Institute
- Royal United Services Institute