A ria is a landform.

Ria or RIA may refer to:

• Ria (given name), a list of people
• Ria (singer), New Zealand 21st century singer

• Astro Ria, Malaysian pay-TV channel 104
• Ria 89.7FM, a Singaporean radio station
• RIA Novosti, a Russian state domestic news agency
• RIA, formerly Research Institute of America, an American publisher on tax and regulatory matters owned by Thomson Reuters

• RIA (restaurant), Chicago
• Ria Money Transfer, a remittances operator based in California
• Rock Island Armory, a former American military surplus and firearms seller
• Registered investment advisor, United States

• Royal Italian Army, the army of the Kingdom of Italy
• Rock Island Arsenal, army base on the Mississippi River

• Radioimmunoassay
• Rare Isotope Accelerator
• Research into Ageing

• RateItAll, a review website
• Rich Internet Application
• Railway Industry Association, a trade association in the United Kingdom
• Robotic Industries Association

• Regulatory impact analysis, a document assessing the impact of a new government regulation
• Royal Irish Academy, an academic body
• IATA code of Santa Maria Airport (Rio Grande do Sul), Brazil
• RIA, station code of Rhoose Cardiff International Airport railway station, Wales

• Riya, a feminine given name
• Rea (disambiguation)
• Rhea (disambiguation)
• R1A (disambiguation)