| Couillet | |
| Settlement Type: | Former municipality of Belgium |
| Pushpin Map: | Belgium |
| Pushpin Label Position: | bottom |
| Pushpin Map Caption: | Location in Belgium |
| Subdivision Type: | Country |
| Subdivision Name: |  Belgium |
| Subdivision Type1: | Region |
| Subdivision Type2: | Community |
| Subdivision Type3: | Province |
| Subdivision Type4: | Municipality |
| Subdivision Name4: | Charleroi |
| Unit Pref: | Imperial |
| Area Total Km2: | 12.47 |
| Population As Of: | 2001 |
| Population Total: | 12546 |
| Timezone: | CET |
| Utc Offset: | +1 |
| Timezone Dst: | CEST |
| Utc Offset Dst: | +2 |
| Coordinates: | 50.4°N 30°W |
| Postal Code Type: | Postal code |
| Postal Code: | 6010 |
| Area Code: | 071 |
Couillet (in French pronounced as /kujɛ/; Walloon: Couyet) is a town of Wallonia and district of the municipality of Charleroi, located in the province of Hainaut, Belgium.
It was a municipality of its own before the merger of the municipalities in 1977.
The local theater company playing in Walloon language, the "Cercle (royal) wallon de Couillet", won the "Grand Prix du Roi Albert I" Walloon-speaking theater contest in 1932, 1952 and 1976.