Liernu is a village of Wallonia and a district of the municipality of Éghezée, located in the province of Namur, Belgium.
Liernu is best known for its centuries old Big Oak Tree (50.5841°N 4.8277°W),[1] one of the largest and oldest in continental Europe. The tree took part in the "European Tree of the Year" competition in 2016[2] as a representative of Belgium.
Liernu had 806 inhabitants as of March 2006, and extends over .