Lac Hieronymus is a Lake located in Lac-Nilgaut; Pontiac, Quebec.

• Latitude: 46° 33' 23'' North   (decimal: 46.5563889)
• Longitude: 77° 37' 29'' West   (decimal: -77.6247222)
• Topography Feature Category: Lake
• Geographical Feature: Étang
• Canadian Province/Territory: Quebec
• Location: Lac-Nilgaut; Pontiac
• Atlas of Canada Locator Map: Lac Hieronymus
• GPS Coordinate Locator Map: Lac Hieronymus Lat/Long