White has previously been special adviser to Conservative cabinet members William Hague, Andrew Lansley and Patrick McLoughlin.
White starts his new role today (7 April) and will work with recently promoted managing director of public affairs, Naomi Harris, and associate director Natasha Graham.
Bellenden’s recent client wins include National Accident Helpline, Akzo Nobel, the Licensed Taxi Drivers Association and the Non-Fossil Fuel Purchasing Agency.
Bellenden chief executive Mark Glover said: "We have ambitious plans for growth and are delighted that Chris, with his detailed knowledge and understanding of politics and the parliamentary process, is joining our industry leading public affairs division, which prides itself on delivering communications excellence in partnership with our clients.
"You can expect further announcements on new hires to our 20-strong public affairs team as we continue to push forward into this exciting new chapter for the company."