John Agar may refer to:
John Agar (1921-2002), American actor John G. Agar (lawyer) (1856-1936), American lawyer John Samuel Agar (1773–1858), English portrait painter and engraver John Agar-Hamilton (1895-1984), South African historian and priest Jonathan Agar, chief executive of Birketts Jon Agar, lectured at Wilkins-Bernal-Medawar Lecture