Sharon Janny den Adel was born on 12 July 1974 in Waddinxveen, Netherlands. She traveled extensively in her youth, living in at least ten different countries, including Indonesia, where she lived between ages one and six. From the age of 14, she performed with various bands, including a blues rock band called Kashiro. During high school Den Adel met Robert Westerholt who introduced her to Paradise Lost. As their partnership grew, in 1996 they came to form a band called The Portal, though the name was changed to Within Temptation before their debut recording. She has a bachelor's degree in fashion design.
Den Adel and long-term partner Robert Westerholt have three children together (daughter Eva Luna, sons Robin Aiden and Logan Arwin), and they currently live near Hilversum. Den Adel was pregnant with their first child, Eva Luna (born 7 December 2005), during The Silent Force tour. On 22 February 2009, Den Adel announced that she was pregnant with her second child, Robin Aiden Westerholt, whose birth was announced on the band's official website on 1 June 2009. Going by the name of Aiden, he was born prematurely at 32 weeks and 6 days. On 26 November 2010, Den Adel announced that she was expecting another child which, due to complications with her previous pregnancies, meant that the band's 2011 tour dates would be rescheduled from spring until autumn. The birth of her son, Logan Arwin, was announced on 31 March 2011.