The Convention of 5 October 1961 Abolishing the Requirement of Legalisation for Foreign Public Documents, also known as the Apostille Convention, is an international treaty drafted by the Hague Conference on Private International Law (HCCH). The Apostille Convention is intended to simplify the procedure through which a document, issued in one of the contracting states, can be certified for legal purposes in the other contracting states of the Convention. A certification under the Convention is called an apostille or Hague apostille. An apostille is an international certification comparable to a notarisation, and may supplement a local notarisation of the document. If the Convention applies between two states, an apostille issued by the state of origin is sufficient to certify the document, and removes the need for further certification by the destination state.

A notary public of the common law is a public officer constituted by law to serve the public in non-contentious matters usually concerned with general financial transactions, estates, deeds, powers-of-attorney, and foreign and international business. A notary's main functions are to validate the signature of a person ; administer oaths and affirmations; take affidavits and statutory declarations, including from witnesses; authenticate the execution of certain classes of documents; take acknowledgments ; provide notice of foreign drafts; provide exemplifications and notarial copies; and, to perform certain other official acts depending on the jurisdiction. Such transactions are known as notarial acts, or more commonly, notarizations. The term notary public only refers to common-law notaries and should not be confused with civil-law notaries.