In the Mediterranean… Battle of Cape Matapan. There is a long-range engagement between Pridham-Wippell's force and some of the Italian cruisers. The Italians suspect that a large British force is present and begin to retire. In the afternoon Swordfish aircraft from the Formidable attack the Italian ships, hitting the battleship Vittorio Veneto and the cruiser Pola. The Vittorio Veneto is able to proceed at reduced speed but the Pola is stopped. In the evening Iachino sends the cruisers Zara and Fiume and for destroyers back to help the Pola. The British ships are pressing on in pursuit hoping to come up with the damaged Vittorio Veneto when, during the night, they find the three Italian cruisers and their escorts on radar. The British approach to close range, without being sighted in return, and in a brief gun battle the cruisers and two destroyers are sunk before they can return fire.

In Belgrade… The British Chief of Staff, General Dill, is in Belgrade for talks with the Yugoslav authorities, but there is little he can offer them and no agreements of any importance are reached.