Florit served as a professor (1929–1954) and later the dean of theology and vice-rector (1951–1954) at the Pontifical Lateran University, while also doing pastoral work in Rome.

He received his episcopal consecration on the following 12 September from Cardinal Clemente Micara, with Archbishop Luigi Traglia and Bishop Emilio Pizzoni serving as co-consecrators, in the Lateran Basilica.

Florit succeeded the late Elia Dalla Costa as Archbishop of Florence on 9 March 1962, and then attended the Second Vatican Council until 1965.

During the council, he was heavily involved with the drafting of Dei verbum, the Dogmatic Constitution on Divine Revelation.

In 1968, the cardinal engaged in a dispute with the popular Florentine priest Enzo Mazzi, whose rebellious attitude the former saw as a threat to "ecclesiastical unity".