Ham (French pronunciation: [am]; Picard: Hin) is a commune in the Somme department in Hauts-de-France, northern France.

The population data given in the table and graph below for 1962 and earlier refer to the commune of Ham excluding Estouilly and Saint-Sulpice.

From April 7 to June 3, 1917, Ham was home to the Lafayette Escadrille The first stone ramparts were put up in the 13th century by the local nobleman, Odon IV.

In the 15th century, the château was transformed into a formidable fortress by John II of Luxembourg, Count of Ligny.

In 1465, John's nephew, Louis of Luxembourg, built a huge donjon, 33m high, 33m in diameter with walls 11m thick.