The new healthcare unit, WPP Health & Wellness, is being overseen by global CEO Mike Hudnall.
It is being formed by the merger of several WPP firms: Ogilvy CommonHealth Worldwide, Sudler & Hennessey, ghg | greyhealth group, and media-planning specialist CMI/Compas.
All four agencies will operate under their respective brands, but will now share services and resources, WPP said.
In the US, the current agency chiefs will be kept in place. However, former ghg | greyhealth group CEO Claire Gillis will lead the international division, which includes hubs in Europe, Asia Pacific, Africa, the Middle East, Australia and New Zealand.
"This new structure centres on keeping those brands and cultures alive, builds on those strengths, and enables new cross-agency collaboration that will benefit our clients," Hudnall said.
The data and insights resource will include input from data consultancy Kantar, media investment firm GroupM, and digital agency Wunderman. It is designed to provide clients with "the ability to change behaviour and deliver better health outcomes", a WPP release said.
Meanwhile, the health consulting service will be focused on providing "innovative, pragmatic strategic counsel for clients' increasingly complex needs", WPP added.
WPP CEO Sir Martin Sorrell said: "This new unit is significant because it represents the next evolution of horizontality, through which WPP will continue to lead and transform health marketing."
Last week WPP announced it had won a $600m (£476m) global comms partnership with pharmacy giant Walgreens Boots Alliance. WPP-owned agencies Finsbury, Ogilvy and Burson-Marsteller will handle PR as part of the deal.