The siege of Mirandola took part in 1551, carried on by Pope Julius III against the city, which had allied with France during the last of the Italian Wars.

As during the War of the League of Cambrai, the fortified city-state of Mirandola had again allied with France.

Like his predecessor Julius II had made in 1511, Pope Julius III in 1551 sent against it an army under generals Camillo Orsini and Alessandro Vitelleschi, along with his nephew, Giovanni Battista del Monte, who later proved inept at military matters.

Despite the alliance with the Emperor Charles V and his imperial support, the siege dragged on for months due to rivalry between the papal commanders.

In Spring, the siege continued with no result, waiting for a corps of Landsknechts to be sent by Charles from Germany.