The Roman Catholic Diocese of Lucknow (Latin: Lucknoven(sis)) is a diocese located in the city of Lucknow in the ecclesiastical province of Agra in India.

The Cathedral School of Lucknow is located in the same compound as St. Joseph's Cathedral.

• Bishops of Lucknow (Latin Rite)
  • Bishop Gerald John Mathias (8 November 2007 – present)
  • Bishop Albert D’Souza (later Archbishop) (21 November 1992 – 16 February 2007)
  • Bishop Alan Basil de Lastic (later Archbishop) (2 July 1984 – 19 November 1990)
  • Bishop Cecil DeSa (later Archbishop) (5 June 1971 – 11 November 1983)
  • Bishop Albert Conrad De Vito, OFMCap (first bishop, 12 December 1946 – 16 November 1970)
  • Bishop Joseph Angel Poli, OFMCap (later archbishop) (Apostolic administrator, 1940 – 1946)