Bell-Jack joins from Carnival stablemate Cunard, where she currently serves in the line's business development team.
She brings additional sales experience from another Carnival brand, P&O Cruises, in both the UK and Australia, as well as expertise developing and nurturing trade partnerships.
In her new role, Bell-Jack will support Princess's business development team and help deliver the brand's strategic sales priorities.
Taking up her role on 21 September, she will report into Princess's Senior Sales Manager Sophia Lief.
Yas McKechnie, Princess Sales Director UK, Ireland and EMEA, said Bell-Jack's "broad experience" with several Carnival rands, strong trade relationships and clear commercial focus made her an ideal candidate to help Princess achieve its growth plans.
"Her commitment to championing travel agents will strengthen how we support our partners, create value for the trade and bring the Princess Cruises experience to even more guests."
Bell-Jack added: "I have always valued the expertise and influence of travel agents, and I look forward to working closely with our partners to help them grow their businesses, inspire their customers and introduce more guests to everything Princess Cruises has to offer."