Sheldon, who has formerly worked at PR firms Hill & Knowlton and Porter Novelli and drugs giant Pharmacia, is poised to join the independent London agency on 4 April.
The American will relocate from New York to work for Resolute clients such as Shire Pharmaceuticals, in addition to helping with 'business development'.
Most recently, Sheldon has worked at independent New York PR firm Lippe Taylor, which he helped expand into healthcare PR, working for clients such as Bayer, Digene, Ortho-McNeill and Procter & Gamble.
Prior to joining Lippe Taylor in September 2002, Sheldon was general manager at Hill & Knowlton New York, working for clients that included Aventis.
Before that, he was executive vice-president and healthcare practice head at Porter Novelli in New York, where he managed a 60-person team.
He moved to New York after 18 years with Pharmacia (formerly Upjohn), where he held a series of corporate and marketing positions, such as director of worldwide human health PR.
Resolute joint managing director and founding partner Anna Korving described Sheldon's track record across more than 25 years in in-house and agency roles as 'unparalleled'.
News of Sheldon's impending arrival comes just a week after it emerged that med ed specialist Dr Leo Francis, formerly president of OCC Europe, is to join Resolute as a board director (PRWeek, 11 March).
Resolute was founded by Korving and joint managing director Paul Blackburn just over three years ago.