Welsum is a village on the left bank of the river IJssel in the present municipality of Olst-Wijhe in the Dutch province of Overijssel. The village is the source of the Welsummer chicken breed. In 2001, a number of farms culled their flocks in connection with the outbreak of foot-and-mouth disease. The earliest existing written mention of the village dates from 1295. The tower of the Protestant church was built around 1475.