Women dominate the top three spots in this year's list and they also make up more than half of the top ten.
A new entrant this year is Elliot Dunster, who was promoted to become comms chief for the influential ABPI trade association in January.
Dunster’s previous career has seen him work in Parliament, as well as with charities; a background that should serve him well in his current role.
Another new entrant to the Top Ten is WPP's international head of health, Claire Gillis, who has over a 1,000 people who report in to her globally.
More from the 2019 Power Book: