| Lierneux | |
| Map: | Lierneux Liège Belgium Map.svg |
| Map-Legend: | Location of Lierneux in the province of Liège |
| Arrondissement: | Verviers |
| Nis: | 63045 |
| Mayor: | André Samray |
| Majority: | Lierneux en Mieux ! |
| Postal-Codes: | 4990 |
| Telephone-Area: | 080 |
| Web: | www.lierneux.be |
| Coordinates: | 50.2833°N 53°W |
Lierneux (in French pronounced as /ljɛʁnø/; Walloon: Lierneu) is a municipality of Wallonia located in the province of Liège, Belgium.
On January 1, 2006, Lierneux had a total population of 3,367. The total area is 92.08 km2 which gives a population density of 37 inhabitants per km2. Lierneux is known for its psychiatric hospital CHS l'Accueil.
The municipality consists of the following districts: Arbrefontaine, and Bra, and Lierneux.
Within the bounds of the municipality a lies a memorial site to the tribute of the 82nd Airborne Division who won the Battle of the Bulge against the German SS division December 22, 1944.