In August 1942, the town of Newhaven played a major part in the ill-fated Dieppe Raid, described officially as a 'reconnaissance in force'. Some 5,000 troops, including many units of the Canadian Army, British Commandos and a small token force of US Rangers, were ordered to capture the French port of Dieppe, hold it for 24 hours and then withdraw. Of those 5,000 only 1,400 returned from the raid.

Troops and tanks involved in the Raid had left from Newhaven and most of the survivors returned to the port. Among the casualties was Lieut. Edwin Loustalot of the US Rangers, the first American soldier to be killed in Europe during the war.