Lavilledieu (French pronunciation: [lavildjø]; Occitan: Laviladieu) is a commune in the Ardèche department in southern France.Lavilledieu is situated in the district of Villeneuve-de-Berg.

Located near the Rhône valley, it is one of the numerous localities crossed by the National Route 102, a highway linking important traffic between Montélimar and Puy-en-Velay.

Lavilledieu is separated from other French cities by the following distances in kilometers: Lavilledieu borders six other communes,[3] all located in the Ardèche department, and geographically broken down as follows: The Auzon commune crosses the municipal territory from its source in the Coiron plateau before rejoining the Ardèche (right bank) at Lanas along a north-south axis.

Between 1991–2020, the average annual temperature observed at the nearest Météo-France meteorological station, “Mirabel Sa”, in the commune of Mirabel, 5 km as the crow flies, is 13.4°C and the average annual cumulative precipitation was 998.1 mm.

The municipality's climate parameters estimated for 2050 according to different greenhouse gas emission scenarios can be consulted on a dedicated site published by Météo-France in November 2022.