The OANDA Corporation states that the currency people use in Belgium is the euro, which replaced the Belgian franc as the official currency of the country in 2002. All countries in the Eurozone have the euro as their official currency.
The transition from the Belgian franc to the euro began in 1999, when Belgium pegged its franc to the euro at the rate of 40.3399 Belgian francs per euro. According to the OANDA Corporation, Belgium initially introduced the franc after it achieved independence in 1832. The Eurozone is not the first monetary union Belgium has belonged to; the country became part of the Latin Monetary Union in 1865, alongside France, Italy and Switzerland. In that union, unlike the Eurozone, Belgium kept the franc as its official currency.