Church built by the Medici near their noble palace, nowadays named Palace Medici Riccardi. Its construction was committed to Filippo Brunelleschi in 1420 by the father of Cosimo il Vecchio (the Old) and was devoted to San Lorenzo, one of recurring names in the Medici family.

The facade of the church, like many other churches in Florence, remained rough and was not covered with marbles. The interior represents the purest and most strict example of Brunelleschi's Renaissance style, with parallel trabeation and round arches carried by Corinthian columns and striped pilasters. This style find its maximum expression inside the Sagrestia Vecchia (Old Sacristy) at the end of the left arm of transept, with sculpure decorations by Donatello.

Inside the nave there are two bronze pulpits by Donatello too, examples of great virtuosity and with a strongly dramatic representation. From left aisle of the church we get inside the Biblioteca Medicea (Medici's Library) or Laurenziana, founded by Cosimo the Old and enlarged by Lorenzo il Magnifico (Lorenzo the Magnificient). The entrance shows the extraordinary stairway projected by Michelangelo and built by Ammannati in 1539 strictly following the original drawings.

To the complex of San Lorenzo belong also the so-called Cappelle Medicee (Medici's Chapels): la Cappella dei Principi (Princes' Chapel), which contains the tombs of the Medici starting from Cosimo the First; and the Sagrestia Nuova (New Sacristy), first architectural work by Michelangelo with the tomb monuments of Giuliano and Lorenzo dei Medici (respectively son and nephew of Lorenzo the Magnificient) decorated with the famous allegorical statues of Giorno (Day), Notte (Night), Crepuscolo (Sunset) and Aurora (Sunrise).