The Institute of Field Archaeologists is an organisation of archaeologists in the United Kingdom.

It was founded on 21st December 1982 as a trade body to represent the profession. Membership is by election following a satisfactory demonstration of archaeological experience and an undertaking to abide by the Institute's Code of Practice. The IFA's aims are to advance the practice of archaeology and allied fields, to define and maintain professional standards of work and to improve education, training and outreach opportunities

The IFA offers three corporate grades of membership; Practitioner (PIFA) grade is intended for excavators and those at the beginning of their career, Associate members (AIFA) are generally of project officer or site supervisor grade and full Members (MIFA) are most experienced, for example project managers and County Archaeologists. Affiliate and Honorary membership is also available for students and retired archaeologists. Corporate members are permitted to use the relevant four letter abbreviation after their names and have voting rights with in the Institute.

The IFA organises conferences and outreach and training initiatives as well as offering advice to the government. It publishes a magazine called The Archaeologist and runs a scheme of Registered Archaeological Organisations who reach a certain standard.

Critics contend that the IFA has done little to improve the pay and conditions of low-ranking archaeologists. It has also been unwilling to discipline members who have transgressed the code of conduct. The IFA itself argues that it can only work effectively if all British archaeologists join it and that progress can only be made through dialogue rather than conflict.