Johanna Charlotte Wessels (born 13 May 1987) is the lead vocalist and primary lyricist of the Dutch symphonic metal band Delain. She was previously a member of gothic metal band To Elysium, before the band's split. She formed Delain in 2005 with former Within Temptation pianist Martijn Westerholt. She is a cousin of Dutch hardcore DJ DaY-már.
Wessels has been trained in both jazz singing and classical singing. She was first trained in jazz, but later her instructor suggested classical singing to her. However, Wessels has stated that she found classical training to be very restrictive, and so she likes to do something "in between the classical and the jazz stuff, and if you look at classical music with high vocal lines, then you kind of get to gothic very soon!"