Olivier Chastel (born 22 November 1964, in Liège) is a Belgian pharmacist and politician of the Liberal Party "Mouvement Réformateur" (MR) who has been serving as a Member of the European Parliament since 2019.

After finishing his studies at the Athénée Royal in Charleroi in 1982, Chastel graduated in Pharmacy at the Université Libre de Bruxelles in 1987.

In 1998, Chastel scaled back his professional activities and became involved with local politics, combining this new challenge with his passion for tennis and for breeding the Flanders Cattle Dog "Bouvier des Flandres".

As the president of the Petitions Commission, he supported the tasks of the Federal Ombudsmen, charged with the simplification of the relations between the authorities and citizens.

From February until July 2004, Chastel briefly held the position of minister of arts, literature and audiovisual matters in the French Community of Belgium.

On 20 March 2008, Chastel was appointed State Secretary for European Affairs in the government of Prime Minister Herman Van Rompuy.