The Squarcialupi Codex (Florence, Biblioteca Medicea Laurenziana, MS Mediceo Palatino 87) is an illuminated manuscript compiled in Florence in the early fifteenth century. It is named for the noted fifteenth-century organist Antonio Squarcialupi, who owned it.
It is the single largest primary source of secular polyphonic music of the Trecento – the Italian ars nova – and contains the largest surviving collection of the compositions of Francesco Landini. The illuminated portraits of the musicians are attributed to Lorenzo Monaco and his circle. It is not known by whom, for what purpose, nor under whose patronage the compilation was made.