Jason de Vos began his professional career in 1990 as a 15-year-old high schooler with hometown club the London Lasers of the former Canadian Soccer League (CSL).

Known for his ability in the air, De Vos spent the next five seasons with the Montreal Impact of the then American Professional Soccer League, the last two on loan to English Third Division club Darlington.

[2] Following an injury-plagued 2003–04, which saw Wigan just miss out on a Premier League play-off place, De Vos left on a Bosman transfer and joined Ipswich Town.

Since joining Ipswich, he held down a regular place in the centre of defence, often playing through many injuries and even captaining the team in Jim Magilton's absence.

After the final match of the 2007–08 season in the 1–0 win over Hull City, De Vos announced his immediate retirement from playing to take up a media role in his native Canada and was given a guard of honour and standing ovation during the teams parade lap of the pitch.

[11] On May 4, de Vos stepped down as Technical Director at Oakville Soccer Club after accepting a full-time position with TSN as a broadcaster.