In law, certiorari is a court process to seek judicial review of a decision of a lower court or government agency. Certiorari comes from the name of an English prerogative writ, issued by a superior court to direct that the record of the lower court be sent to the superior court for review. The term is Latin for "to be made certain", and comes from the opening line of such writs, which traditionally began with the Latin words "Certiorari volumus..." ("We wish to be made certain...").
Derived from the English common law, certiorari is prevalent in countries utilising, or influenced by, the common law. It has evolved in the legal system of each nation, as court decisions and statutory amendments are made. In modern law, certiorari is recognized in many jurisdictions, including England and Wales (now called a "quashing order"), Canada, India, Ireland, the Philippines and the United States. With the expansion of administrative law in the 19th and 20th centuries, the writ of certiorari has gained broader use in many countries, to review the decisions of administrative bodies as well as lower courts.
The term certiorari (US English: ˌsɜːrʃiəˈrɛəri, -ˈrɑːrI, or -ˈrɛəraɪ; UK English: ˌsɜːrtiəʊˈrɛəraɪ or -ˈrɑːrI) comes from the words used at the beginning of these writs when they were written in Latin: certiorārī [volumus] "[we wish] to be made certain". Certiorari is the present passive infinitive of the Latin verb certioro, certiorare ("to inform, apprise, show"). It is often abbreviated cert. in the United States, particularly in relation to applications to the Supreme Court of the United States for review of a lower court decision.
Historical usage dates back to Roman Law. In Roman law, certiorari was suggested in terms of reviewing a case—much as the term is applied today—although the term was also used in writing to indicate the need or duty to inform other parties of a court's ruling. It was a highly technical term appearing only in jurisprudential Latin, most frequently in the works of Ulpian.