Notary, NOH tuhr ee, public is an officer authorized by state law to certify certain documents and to take oaths. Many documents, such as deeds, must be notarized before they become legally effective. The purpose of notarizing a document is to protect those who use it from forgeries. The notary signs the document to certify that the individual who signed it appeared in person and swore to the notary that the signature on the document is genuine. The notary records that fact, then stamps a seal on the document.