The Côte de Trieu (in French) or Knokteberg (in Dutch) is a hill in the municipality of Mont-de-l'Enclus, in the Belgian province of Hainaut.

The road of the Côte de Trieu is on the south side of the Kluisberg, one of the hill formations in the Flemish Ardennes.

The climb starts with a gentle slope before gradually steepening to a maximum gradient of 13 % towards the top.

The Côte de Trieu is best known from cycling, as it is a regular climb in the Flemish races in spring and is sometimes included in the Tour of Flanders.

Since 2018 it features three times in Dwars door Vlaanderen, where it acts as a strategic launchpad at 33 km from the finish.