On the Western Front... German forces begin a significant counterattack from east of Mortain, opposite US 1st Army (between US 7th and 14th Corps). Elements of German 2nd and 116th Panzer Divisions spearhead the offensive. Mortain is recaptured. Heavy Allied air attacks prevent more significant advances by the German forces. Meanwhile, in Brittany, the US 8th Corps (part of US 1st Army) attacks the German garrisoned ports of Brest, St. Malo and Lorient. During the night, Canadian forces (part of British 21st Army Group) launch attacks southwest of Caen after a preparatory bombardment involving over 1000 RAF heavy bombers dropping more than 3000 tons of bombs on German positions.

On the Eastern Front... Soviet forces advance in the Carpathian foothills and capture Sambor, southwest of Lvov.

In the Mariana Islands... On Guam there is heavy fighting along the entire front as US forces attack Japanese positions.