Hainaut (Dutch: Henegouwen; German: Hennegau) is one of the 11 multi-member constituencies of the Chamber of Representatives, the lower house of the Belgian Federal Parliament, the national legislature of Belgium.

The constituency currently elects 18 of the 150 members of the Chamber of Representatives using the open party-list proportional representation electoral system.

At the 2019 federal election the constituency had 942,789 registered electors.

Hainaut currently elects 18 of the 150 members of the Chamber of Representatives using the open party-list proportional representation electoral system.

[6][7] Only parties that reach the 5% threshold in the constituency compete for seats.