Graham Douglas Leonard KCVO PC DL[1] (8 May 1921 – 6 January 2010) was an English Roman Catholic priest and former Anglican bishop.
He was conditionally ordained to the priesthood in the Roman Catholic Church and was later appointed a monsignor by Pope John Paul II.
During the Second World War he was commissioned into the Oxfordshire and Buckinghamshire Light Infantry, rising to the rank of captain.
He spent the latter part of the war attached to the Army Operational Research Group for the Ministry of Supply.
His long association with the Diocese of London began in 1962 when, before becoming the Bishop of Willesden (a suffragan bishopric in the diocese) in 1964, he was appointed as Archdeacon of Hampstead and as rector of St Andrew Undershaft with St Mary Axe in the City of London.
[15] This eased his reception into the Roman Catholic Church, although his claim that he was legitimately a bishop and his request for a personal prelature were rejected.