Homologation (Greek homologeo, ὁμολογέω, "to agree") is the granting of approval by an official authority. This may be a court of law, a government department, or an academic or professional body, any of which would normally work from a set of rules or standards to determine whether such approval should be given. The word may be considered very roughly synonymous with accreditation, and in fact in French and Spanish may be used with regard to academic degrees (see apostille). Certification is another possible synonym, while to homologate is the infinitive verb form.

In today's marketplace, for instance, products must often be homologated by some public agency to assure that they meet standards for such things as safety and environmental impact. A court action may also sometimes be homologated by a judicial authority before it can proceed, and the term has a precise legal meaning in the judicial codes of some countries.

The equivalent process of testing and certification for conformance to technical standards is usually known as type approval in English-language jurisdictions.

Another usage pertains to the biological sciences, where it may describe the similarities used to assign organisms to the same family or taxon, similarities they have jointly inherited from a common ancestor.