Sant'Andrea Church, Former Catholic church in Melzo, Italy.

Sant'Andrea in Melzo is a rectangular church with stone walls and a single nave, its Gothic-Lombard structure altered to Baroque in the 18th century. The apse holds frescoes of the late 15th century and later cycles: the 1524 work of Nicola Mangone, called il Moietta, and Octavio Semino's paintings dated 1574. A brick facade with a pale stone portal and a tall framed window stands beside a yellow plastered section with a square bell tower.

The building dates to the 11th or 12th century and was initially built as a private chapel by local citizens who held patronage rights. It later became a religious site that witnessed shifts in local devotion and artistic patronage across the medieval and early modern periods.

The apse frescoes carry the Cross of Saint Andrew and, beneath Saint Anthony Abbot, a square-and-circle symbol also found in Leonardo da Vinci's Codex Atlanticus. The local Amici di Sant'Andrea association reads the offerers in the triptych as Caterina Sforza Riario and her husband Girolamo Riario, linking the paintings to the 1476 conspiracy against her father, Duke Galeazzo Maria Sforza.

The building stands on Via A. Pasta in Melzo and is accessible to visitors interested in religious art and architecture. Allow time to examine the frescoes carefully, as the painted details reward close observation.

During restoration work in 1980, workers discovered a skull in the apse that sparked investigations into a possible connection to Duke Galeazzo Maria Sforza. This mysterious finding still raises questions about the site's role in local power and authority.