The Unfair Contract Terms Act 1977 (c 50) is an Act of Parliament of the United Kingdom which regulates contracts by restricting the operation and legality of some contract terms. It extends to nearly all forms of contract and one of its most important functions is limiting the applicability of disclaimers of liability. The terms extend to both actual contract terms and notices that are seen to constitute a contractual obligation.

Under this regulation, if a clause within the standard terms in use is considered as 'unfair', the clause will be ineffective (or the other party will be entitled to avoid the clause). At court, the clause that is deemed to be unfair will undergo a 'reasonableness' test or an 'unfairness' test.