The corporate group was previously headed by Oliver Pauley, who left his role as managing director of Portland in April to set up his own agency.
Ingleby began working at the agency eight years ago as an account manager and, as partner, has played a pivotal role leading its work with clients such as BAE Systems, O2 and Uber.
He will report to Mark Flanagan, managing director of its corporate and health practices. He will also focus on strengthening the agency’s global corporate offer and client base, working with its other offices in the US, APAC and the EMEA region.
Ingleby said: "I’m delighted to be working with such a strong team and an unrivalled set of clients. The work we do has changed tremendously since I joined, with constant investment in new capabilities."
The corporate group is a team of 75 people with expertise across corporate comms, public affairs and financial comms, as well as a Brexit unit.
A source claimed that Pauley had left the agency after his request to become chief executive was denied, although Pauley himself told PRWeek this version of events was "not accurate".