(Hyppolyte) Louis Alexandre Dechet (alternatively, spelled Dechez; 20 January 1801 in Lyon – 18 October 1830 in Lier) was a French actor and is regarded the author of the lyrics of the Brabançonne, the Belgian national anthem.

He there served with the city guard which was responsible for maintaining law and order.

Dechet is said to have written the text of the Brabançonne during the first revolutionary gatherings at the café "L'Aigle d'Or" in the Brussels Greepstraat in August 1830, shortly after the performance of the opera La Muette de Portici, which triggered the Belgian revolution.

During the Belgian Revolution Dechet became a volunteer in the revolutionary army and joined the corps of Frenchman Charles Niellon.

On the Place des Martyrs/Martelaarsplein in Brussels, a column honouring Dechet is to be found, which was created by the sculptor Alfred Crick and inaugurated in 1897.