Désiré Alfred Mérchez (August 16, 1882 – July 8, 1968) was a male French swimmer and water polo player who competed in the 1900 Summer Olympics.
He was born in Lille and died in Nice.
In 1900 he won the bronze medal with the French team in the 200 metre team swimming. He also participated in the 1000 metre freestyle event but was eliminated in the first round.
As a member of the French water polo team Pupilles de Neptune de Lille #2 he won a second bronze medal at the same Olympics.