1916 - 1970
The Great War brought an increase in traffic in the form of potatoes from Jersey and in 1916 the opening of a Royal Naval Cordite factory nearby saw imports of iron pyrites from Spain and Norway. This traffic continued until 1938.

In 1935 the New Quay was developed on land at Hamworthy, opposite the Town Quay. By 1939, 280 dock workers were employed at the Port. In World War II a flying boat service started in the Harbour when Imperial Airways transferred operations from Southampton Water until 1947.

The Dorset Lake Shipyard at Hamworthy constructed minesweepers during the war, and Poole Quay was also an embarkation point for the D-Day landings. In 1950 an oil storage terminal for J.R. Wood & Company was built on Ballast Quay, this later became known as Corralls.

By 1964 400,000 tonnes of cargo were being unloaded from 1,500 ship visits to the port which then employed over 90 dock workers. The Town Quay was still thriving with the principal imports being timber for Norton Limited and grain for Yeatman's Mill and Christopher Hill's Grain Store. Up to 200,000 tonnes of coal were also imported by the Southern Gas Board annually for use in their works adjacent to the Quay. The Devlin Act of 1968 required ports to employ a permanent workforce and not just casual labour, so PHC became the employer of registered dock workers, of which there were just 46 in 1968.