Unitatis redintegratio (Restoration of unity) is the Second Vatican Council's decree on ecumenism. It was passed by a vote of 2,137 to 11 of the bishops assembled at the Council, and was promulgated by Pope Paul VI on 21 November 1964.
The title of the document is taken from the opening words of the Latin text. The opening words of the official English translation are: "The restoration of unity among all Christians is one of the principal concerns of the Second Vatican Council."