Mario Aerts (born 31 December 1974 in Herentals, Belgium) is a former professional road bicycle racer, who competed between 1996 and 2011. He competed for three teams: Vlaanderen 2002, Team Telekom and the Lotto team through various sponsorships, competing with that particular team for twelve seasons during his career. During this time, he raced in the Tours de France, the Giro d'Italia, and the Vuelta a España. In the 2007 cycling season, he finished in these three major stage races in cycling. He was only the 25th racer in the history of cycling to achieve this.

Aerts won the Grand Prix d'Isbergues in 1996, Circuit Franco Belge in 2001, the Giro della Provincia di Lucca in 2001, and most notably La Flèche Wallonne in 2002; he did not win a professional race after that. In June 2011, he announced his retirement as a professional cyclist at the end of the year, citing heart problems as the major cause. After retiring he would become an assistant for the team he rode for under its present name: Lotto-Soudal.