Andy was Born in Kortrijk, Belgium in 1975. At the age of 10 he started studying saxophone. At the age of 13 he studied 3 years with classical saxophone player Rudy Haemers. After his studies as engineer, he got his first jazz lessons with a saxophone player Frank Debruyne. At the age of 25 he went to the Conservatory of Gent, where he followed lessons with Frank Vaganée, Dieter Limbourg, Marc Godfroid and Nico Schepers. In 2004 he followed master classes with Dick Oatts in Amsterdam, Netherlands. He has also followed  masterclasses with John Ruocco and Bob Mintzer.
He graduated in Gent in 2005 as a Master of Jazz  Music.

Beside Andy Declerck – Kari Antila Group, he has his own Andy Declerck Kwartet and also played/plays in the salsa big band Mucho Gusto, TNO Tuesday Night Orchestra, big band '86, Greenhouse Sextet, Colorless Green, The Almost Swinging JazzBand, and as a freelance musician. He has/had concerts with the Brussels Jazz Orchestra, Hans Van Oost, Frederik Leroux, Herman pardon, The Beethoven Academy. He has perfomed in several Belgian jazzclubs and in the Netherlands, France and Greece. He also teaches in different music schools and lately he has concentrated a lot on composing his own music.

Beside the tenor saxophone he also plays soprano saxophone, flute and clarinet.