Medernach (Luxembourgish: Miedernach) is a small town and former commune in eastern Luxembourg. It is part of the canton of Diekirch, which is part of the district of Diekirch.
Medernach is home to an aerodrome (49°47′20″N 6°14′28″E / 49.78890°N 6.24101°E / 49.78890; 6.24101 (Medernach Airfield)).
As of 2007, the township Medernach has a population of 1107.
Since 2011, Medernach has merged with Ermsdorf to become the "Aerenzdallgemeng" (commune Vallée de l'Ernz, Ernztalgemeinde).