Of agricultural origin, it grew rapidly during the 19th century because of fishing, along with the nearby port of Boulogne-sur-Mer. Sailors of Portel were as numerous as those of Boulogne before World War I. In 1841, two Le Portel sailors were on the ship Belle Poule, that brought back the remains of Napoleon.
During the Second World War, on 8 and 9 September 1943, Le Portel suffered as part of Operation Fortitude, a diversionary manoeuvre by the Allies to fool the Germans into believing the possibility of a landing on the English Channel. The bombings, which destroyed nearly 90% of homes, also killed more than 500 people. On 12 August 1944, Charles de Gaulle was at Le Portel for its liberation. The town received the Croix de guerre with silver star for its sacrifice.
|Census count starting from 1962 : Population without double counting|