Jones founded HJPR with Jonathan Hackford in 2003, having previously worked together for six years at Freuds. Together their clients included One Direction, Little Mix, Jack Whitehall and Davina McCall.
Jones' new agency, Simon Jones PR, will continue to represent One Direction and Little Mix, as well as other clients including Fleur East, Myleene Klass and Ant & Dec.
Meanwhile Hackford is continuing to work with his clients, Jack Whitehall and Davina McCall among others, and will make an announcement about his plans later this month.
One Direction announced in August that the group would shortly split temporarily to pursue solo projects, although they released the album Made in the AM late last year.