Agar, a thickening or jellyfying agent extracted from red algae (microbiology and culinary uses) Agar may also mean:

Hagar, a Biblical character, sometimes misspelled as Agar

Agar, South Dakota

Agar (India)

Wilfred Eade Agar (1882–1951), Anglo-Australian zoologist

James Agar, 1st Viscount Clifden (1735–1788), Irish MP

Edward Agar, conspirator in the Great Gold Robbery of 1855 and character in The Great Train Robbery

Augustus Agar (1890–1968), British recipient of the Victoria Cross

John Agar (1921–2002), American actor and husband of Shirley Temple

Agar (software), a set of open-source libraries for computer graphics