29 April 1998|
|Height||1.89 m (6 ft 2 in)|
|Last updated on: 24 August 2019|
De Geus started playing hockey at Almere where he went through all the youth ranks until he made his debut for the first team. In April 2019, he announced he will leave Almere at the end of the season. One month later he signed a four-year contract at Kampong.
In November 2016, de Geus was selected for the 2016 Junior World Cup, where the team finished seventh. He made his debut for the senior national team at the age of 18 in a test match against South Africa in 2017. He was part of the Dutch team that won the silver medal at the 2018 World Cup. In June 2019, he was selected in the Netherlands squad for the 2019 EuroHockey Championship. They won the bronze medal by defeating Germany 4–0. He was named the under-21 player of the tournament.
- "Jonas de Geus". hockey.nl (in Dutch). Retrieved 9 March 2019.
- "Hockey-internationals Pieters en De Geus verlaten de Almeerse". www.omroepflevoland.nl (in Dutch). Omroep Flevoland. 19 April 2019. Retrieved 3 May 2019.
- "Hockey-international Jonas de Geus naar Kampong". www.omroepflevoland.nl (in Dutch). Almere: Omroep Flevoland. 26 May 2019. Retrieved 1 July 2019.
- Mansier, Jeroen. "Van Dijk en Huybregts vallen af bij Jong Oranje Heren". hockey.nl (in Dutch). Retrieved 9 March 2019.
- "de GEUS Jonas History". tms.fih.ch. International Hockey Federation. Retrieved 9 March 2019.
- "Selectie Heren EK Hockey 2019 bekend". www.knhb.nl (in Dutch). Koninklijke Nederlandse Hockey Bond. 29 July 2019. Retrieved 9 August 2019.
- "Hockeyers verslaan Duitsland weer en pakken brons". www.ad.nl (in Dutch). Algemeen Dagblad. 24 August 2019. Retrieved 24 August 2019.
- "Brilliant Belgium win their first ever European Championship crown". belfiuseurohockey.com. 24 August 2019.