Paul-Marie-Adolphe Costermans (2 April 1860 – 9 March 1905) was a Belgian soldier and colonial civil servant.

After a brief career in the Belgian Army, Costermans enlisted for service in the military of the Congo Free State, the Force Publique, in 1890 and later served in the colony's administration.

A native of Brussels, Costermans attended the Royal Military Academy and was commissioned a sub-lieutenant of artillery in the Belgian Army on 13 December 1880.

On 24 February 1892, having fallen ill, he handed over his command and left Léopoldville for Boma, where he arrived on 10 March.

He explored the territory of the Banfumu people along the Kasai river, which had been relatively neglected owing to the tribe's reported cannibalism.

[1][2] Costermans returned to Europe in September 1903, but re-embarked for the Congo on 5 January 1904 with the title of Vice Governor-General to take over the reins from Félix Fuchs.

His government coincided with the release of the Casement Report, a damning account of atrocities carried out in the Congo Free State.