Knox, who has been riding for Team Wiggins for the last couple of years, has enjoyed a stellar 2017 season, gaining top-tens in a string of prestigious under-23 races, including eighth place overall in the Tour de l’Avenir where he also finished second on one stage.
The 21-year-old has also proved his worth in one-day races, finishing as runner-up in the under-23 version of Liège-Bastogne-Liège in April.
“I am really happy with my season so far. I have managed to take a step up from knocking on the door last year to be close this year with a few second places”, Knox said in a team statement.
“Runner-up in Liège – a race I dream of winning as a pro – was great and from there on to get good results over the whole season gives me motivation and confidence to take the next step up the ladder at Quick-Step Floors.”
Patrick Lefevere, the CEO of the Quick-Step Floors team, said that the team had been monitoring Knox’s development for a number of months.
“James was on our radar for some time and we closely monitored his progression this season, but it wasn’t only his results that caught our attention, also his right attitude and commitment towards the sport were equally impressive.
“He’s a very promising climber and we’ll carefully nurture his talent in the years to come, while at the same time helping him adapt to the demanding pro life.”
Knox is the second young British rider to make the step up to the professional ranks for the 2018 season, with Chris Lawless turning pro with Team Sky after impressing at Axeon Hagens Berman.
The additions of Knox and Lawless to the WorldTour ranks will bring the number of top-level British professionals to 19 for 2018, making Britain the eighth most represented nation in the WorldTour peloton