Marcello Mimmi (18 July 1882 – 6 March 1961) was an Italian Cardinal of the Roman Catholic Church.

Marcello Mimi was born in San Pietro in Casale and studied at the seminary in Bologna before being ordained to the priesthood on 23 December 1905.

He was elevated to a Privy Chamberlain of His Holiness on 19 November 1919, and later named rector of the Regional Seminary of Romagna.

[1] Mimmi later chose to be advanced to the rank of Cardinal Bishop, receiving the suburbicarian see of Sabina e Poggio Mirteto on 9 June 1958.

He was also one of the cardinal electors who participated in the 1958 papal conclave that selected Pope John XXIII.