The Battle of the Solent was a naval battle of the Italian Wars, fought between the fleets of Francis I of France and Henry VIII of England. It was fought on 18 July and 19 July 1545 in the Solent channel off the south coast of England between Hampshire and the Isle of Wight. The engagement was inconclusive and is most notable for the sinking of the English carrack Mary Rose.

In 1545, King Francis I of France launched an invasion of England with 30,000 soldiers in more than 200 ships. Against this armada — larger than the Spanish Armada forty-three years later — the English had about 80 ships and 12,000 soldiers.

The French expedition started disastrously, the flagship Carraquon perishing in an accidental fire at anchor in the Seine on 6 July 1545. Admiral Claude d'Annebault transferred his flag to La Maistresse which then ran aground as the fleet set sail. The leaks were patched and the fleet crossed the Channel. The French entered the Solent and landed troops on the Isle of Wight and the Sussex coast.

On July 18 1545 the English came out of Portsmouth and engaged the French at long range, little damage being done on either side. La Maitresse was on the point of sinking due to the damage she had sustained earlier but although d'Annebault had to change his flagship again she was saved from foundering.

On the night of 18 July King Henry dined aboard Great Harry, the flagship of Admiral John Dudley, Viscount Lisle.

The next day was calm, and the French employed their galleys against the immobile English vessels. Toward evening a breeze sprang up and as Mary Rose, the flagship of Vice Admiral Sir George Carew , advanced to battle she capsized and sank with the loss of all but 35 of her crew. It is theorized that her undisciplined crew had neglected to close the lower gunports after firing at the galleys, so that when she heeled in the breeze she filled with water and turned over. The French believed they had sunk her.

The French troops ashore made no progress and returned to France in August.