is a 16th century palace located in Piazza della Scala, in the centre of Milan
. It has been Milan's city hall since 9 September 1861. It borders on Piazza San Fedele, Piazza della Scala, Via Case Rotte and Via Tommaso Marino.
The palace was built for, and is named after, the Genoan trader and banker Tommaso Marino. It became a property of the State in 1781.
The palace was built from 1557 to 1563 for Tommaso Marino. It was designed by architect Galeazzo Alessi from Perugia
. Its main facade was originally that facing Piazza San Fedele, as Piazza della Scala didn't yet exist; the corresponding area was occupied by buildings.