Wim Mertens (born 14 May 1953) is a Flemish Belgian composer, countertenor vocalist, pianist, guitarist, and musicologist.
Mertens was born in Neerpelt, Belgium. He studied social and political science at the University of Leuven (graduating in 1975) and musicology at Ghent University; he also studied music theory and piano at the Ghent Conservatory and the Royal Conservatory of Brussels.
In 1978, he became a producer at the then BRT (Belgian Radio and Television, now called Vlaamse Radio- en Televisieomroep). For Radio 2 (Radio Brabant) he produced concerts by Philip Glass, Steve Reich, Terry Riley, Meredith Monk, Urban Sax and others, and hosted a program called Funky Town together with Gust De Meyer (with whom he recorded the experimental album For Amusement Only).
Known primarily as a composer since the early 1980s, Mertens is best known for his opus "Struggle for Pleasure". He is also well known for his piece "Maximizing the Audience", which was composed for Jan Fabre's play The Power of Theatrical Madness, which premiered in 1984 in Venice, Italy.