A registrar is an official keeper of records made in a register. The place where such records are made and kept is in many cases known as a register office.

In the art world, the term "registrar" denotes an individual who is professionally involved in the care and management of fine art or ethnographic objects in public and private collections, museums and galleries. A registrar’s duties are multifaceted and may include, but are not limited to, collections inventory and documentation, exhibition coordination, logistical organization for transport, and insurance of loans and courier accompaniment of loans or entire exhibitions travelling to other institutions. In a museum, a registrar functions as the link between curator, conservator/restorer, museum technician and lender.
Registrar may also be a trade name or a term in software design.