Sir John Francis O'Neill Lentaigne CB (21 June 1803 – 12 November 1886) was an Irish administrator, lawyer and Privy Counsellor.
His father was physician Dr. Benjamin Lentaigne of Dominick Street, Dublin, an immigrant from France.
[1] He was one of the first pupils to attend school at Clongowes Wood College.
He graduated from Trinity College and with a medical degree.
[2] He married Mary, the daughter and co-heiress of Francis Magan of Emoe, Westmeath, with whom he had 12 children.