The Roman Catholic Diocese of Xingu-Altamira () is a Roman Catholic diocese located in the area of the Xingu River in the ecclesiastical province of Santarém in Brazil. The cathedral is located in Altamira, Brazil.
On 16 August 1934, the Territorial Prelature of Xingu was established from the Metropolitan Archdiocese of Belém do Pará, Territorial Prelature of SantÃÂssima Conceição do Araguaia and Territorial Prelature of Santarém.
At the time the Diocese of Santarém was promoted to an Archdiocese, the Territorial Prelature of Xingu was suppressed and succeeded by the Roman Catholic Diocese of Xingu-Altamira on 6 November 2019.