Sculptor and architect, he was born in Settignano, near Florence. His father died when he was young. He studied in the Baccio Bendilelli's academy and then with Sansovino in Venice.
Ammannati was introduced by Vasari to the court of pope Giulio III, where he obtained a lot of commissions for sculpture works and he was able to design his first architectures studying the legacy of the ancient Rome.
After the death of Giulio III, in 1555, Ammannati moved with Vasari to the court of Cosimo I de Medici in Florence, where he achieved the building of the great fountain in the Signoria square, inaugurated in 1577.
Above all, in Florence he obtained important architectural works: the expansion of Palazzo Pitti with new apartments and the courtyard, the Holy Trinity bridge and various projects involving other city buildings.
In Lucca, Ammannati worked on the great project of the Elders' Palace, of which he followed the building between 1577 and 1581.