Solarium may refer to:

• A sunroom, a room built largely of glass to afford exposure to the sun
• A terrace (building) or flat housetop
• The Solarium Augusti, a monumental meridian line (or perhaps a sundial) erected in Rome by Emperor Augustus
• A tanning bed or tanning booth, non-medical devices that emit ultraviolet light for the purpose of creating a cosmetic tanning of the skin
• Solarium (constellation), a former constellation
• Solarium (myrmecology), an earthen structure constructed by certain ants for the purpose of brood incubation
• Solarium, a PHP client for interacting with Apache Solr
• Project Solarium, an Eisenhower administration initiative to analyze policy towards the Soviet Union
• Cyberspace Solarium Commission, which works to establish policy solutions to prevent and prepare against cyber attacks.

• Solaria (disambiguation)