An antiquarian or antiquary (from Latin antiquarius 'pertaining to ancient times') is an aficionado or student of antiquities or things of the past. More specifically, the term is used for those who study history with particular attention to ancient artifacts, archaeological and historic sites, or historic archives and manuscripts. The essence of antiquarianism is a focus on the empirical evidence of the past, and is perhaps best encapsulated in the motto adopted by the 18th-century antiquary Sir Richard Colt Hoare, "We speak from facts, not theory."

The Oxford English Dictionary first cites "archaeologist" from 1824; this soon took over as the usual term for one major branch of antiquarian activity. "Archaeology", from 1607 onwards, initially meant what is now seen as "ancient history" generally, with the narrower modern sense first seen in 1837.

Today the term "antiquarian" is often used in a pejorative sense, to refer to an excessively narrow focus on factual historical trivia, to the exclusion of a sense of historical context or process. Few today would describe themselves as "antiquaries", but some institutions such as the Society of Antiquaries of London (founded in 1707) retain their historic names. The term "antiquarian bookseller" remains current for dealers in more expensive old books.