Papal conclave, 1740

Coat of arms during the vacancy of the Holy See
Dates and location
18 February – 17 August 1740 Apostolic Palace, Papal States
Key officials
Dean	Pietro Ottoboni, Tommaso Ruffo
Sub-Dean	Tommaso Ruffo, Lodovico Picco della Mirandola
Camerlengo	Annibale Albani
Protopriest	Armand-Gaston de Rohan-Soubise
Protodeacon	Lorenzo Altieri
Election
Vetoed	Pier Marcelino Corradini
Elected Pope
Prospero Lorenzo Lambertini Name taken: Benedict XIV
← 1730 1758 →

The Papal conclave of 18 February to 17 August 1740, convoked after the death of Pope Clement XII on 6 February 1740, was one of the longest conclaves since the 13th century.

The initial favourite to succeed as Pope, the elderly Pietro Ottoboni (1667–1740), Dean of the College of Cardinals, died shortly after the beginning of the conclave, and cardinals loyal to the House of Bourbon repeatedly proposed Pompeo Aldrovandi, but eventually had to accept that he could not secure two-thirds of the votes.

After six months, other possible candidates had also failed, and Prospero Lambertini, Archbishop of Bologna, who had been a Cardinal since 9 December 1726, was elected. He became the 247th pope of the Holy Roman Church, taking the name of Benedict XIV.

The conclave began on 18 February 1740, following the funeral of Clement XII, and lasted for six months.

Cardinal Acquaviva d'Aragona presented the veto of King Philip V of Spain against Pier Marcelino Corradini being elected.

At the outset, only thirty-two Cardinals entered into the conclave, in which there was an expectation that the elderly Pietro Ottoboni (1667–1740), a Cardinal for more than fifty years and Dean of the Sacred College of Cardinals, would be chosen to succeed Clement XII. However, opposition to Ottoboni was raised because of his protective relationship with France. After a few days he was taken seriously ill, left the conclave on 25 February, and died on 29 February. Ottoboni's place as Dean was taken by Tommaso Ruffo, vice-dean of the Sacred College.