You can fly between Girona Airport and Brussels Main Airport or Charleroi with three different airlines: Jetairfly, Thomas Cook Airlines and Ryanair.
Given that there are three airlines to choose from, you should be able to find a flight to suit you. Ryanair usually offers the cheapest rates out of all the airlines, and also offers the most frequent flights. There is one flight early in the morning from each destination, and one each in the afternoon.
Please bear in mind that Ryanair has a limited luggage policy and extra luggage sufficiently bumps up the price. Ryanair flies to Brussels Charleroi, which is 46km away from the city centre than Brussels main airport, whereas the main airport is only 14km away. Brussels Airlines, Vueling, Thomas Cook Airlines and Clickair (with Iberia) also fly to Barcelona´s main airport from Brussels main airport, so these might be more convenient options.
For more information and to help you choose the best airline for you, please see our Companies section under Flight Destinations.