Antonio Francesco Grazzini (March 22, 1503 - February 18, 1583), was an Italian author.

He was born at Florence of a good family, but there is no record of his upbringing and education. He probably began to practise as an apothecary as a youth. In 1540 he co-founded the Academy of the Humid (degli Umidi) afterwards called della Fiorentina, and later took a leading role in the establishment of the more famous Accademia della trusca. To both societies he was known as Il Lasca or Leuciscus, a pseudonym which is still frequently substituted for his proper name.

Grazzini was temperamental, his life consequently enlivened or disturbed by various literary quarrels. His Humid brethren expelled him for a time from their society, because of his ruthless criticism of the Arameans, a party of academicians who maintained that the Florentine language was derived from Hebrew, Chaldee, or some other branch of the Semitic. He was readmitted in 1566, when his friend Salviati was consul.

II Lasca ranks as one of the great masters of Tuscan prose. His style is flexible and abundantly idiomatic, but without affectation. It has the force and freshness of popular speech, whilst retaining a flavour of academic culture. His principal works are:

• Le Cene (1756), a collection of stories in the manner of Boccaccio, and a number of prose comedies
• La Gelosia (1568)
• La Spirit ala (1561)
• I Parent adi
• La Arenga
• La Sibilla
• LaPinzochera
• L'Arzigogolo

The stories, though of no special merit as far as the plots are concerned, are told with verve and interest. A number of miscellaneous poems, a few letters and Four Orations to the Cross complete the list of Grazzini's extant works.

He also edited the works of Francesco Berni, and collected Tutti I trionfi, larri, mascherate, e canti carnasciataschi, andati per Firenze dal tempo del magnifico Lorenzo de 'Medici fine all anno 1559. In 1868 Adamo Rossi published in his Ricerche per le biblioteche di Perugia three novelle by Grazzini, from a manuscript of the 16th century in the Comunale of Perugia; and in 1870 a small collection of those poems which have been left unpublished by previous editors appeared at Poggibonsi, Alcune Foesie inedite. See Pietro Farifani's Vita del Lasca, prefixed to his edition of the Opere de A. Grazzini (Florence, 1857).