The Arrondissement of Mons (French: Arrondissement de Mons; Dutch: Arrondissement Bergen) is one of the seven administrative arrondissements in the Walloon province of Hainaut, Belgium.

Arrondissement of Mons Arrondissement de Mons
Arrondissement of Belgium
Location of the arrondissement in Hainaut
Coordinates: 50°27′N 3°51′E / 50.45°N 3.85°E / 50.45; 3.85
Country	Belgium
Region	Wallonia
Province	Hainaut
Municipalities	13
Area
• Total	583.99 km2 (225.48 sq mi)
Population  (1 January 2017)
• Total	258,431
• Density	440/km2 (1,100/sq mi)
Time zone	UTC+1 (CET)
• Summer (DST)	UTC+2 (CEST)

It is both an administrative and a judicial arrondissement. However, the Judicial Arrondissement of Mons also comprises all municipalities of the Arrondissement of Soignies but one (Lessines), as well as the municipalities of Brugelette en Chièvres of the Arrondissement of Ath.