Gittins has been hired as group MD of the agency’s Health and BioScience practice following Edelman's promotion of Steven Spurr from the job to the role of chief operating officer.
Currently MD of Red Health, which he set up with colleague Pat Pearson in 2007, Gittins will make the move in September.
Spurr will continue to handle both the MD and COO roles until then, at which point alongside his COO role he will also become chairman, Edelman Health UK.
Praising Gittins' ‘strategic insight, leadership skills and belief', Spurr said: ‘Paul is a proven creative health innovator and adding his expertise and passion to this industry-leading team will only strengthen Edelman’s health offering.’
Gittins has a background in pharmacology, providing consultancy to pharmaceutical companies, charities and trade bodies.
He said one focus of his new work would be ‘injecting creativity and consumer understanding into health campaigns’.
Red deputy CEO Amanda Duncan said a replacement would be announced in due course, adding: 'We’ve been aware for a while that he was looking for a new challenge and have been supportive of his decision to move on.'