McIntyre will be based in New York and will report into chairman and global CEO Paul Taaffe.
In his new capacity, McIntyre will drive the firm's growth strategy in healthcare and will become a member of the firm's Global Council.
McIntyre joins H&K from integrated marketing comms agency Global Prairie, where he was a partner. He has more than 30 years of working in the industry for companies including Fleishman Hillard, Wyeth, MeadWestvaco, Pharmacia, Bayer, American Home Products and Hoffmann LaRoche.
Taaffe said of McIntyre's appointment: ‘Dan's experience is key as H&K responds to the needs of our growing healthcare roster. Our clients face some of the toughest challenges globally such as litigation, regulatory oversight, risk communications, reimbursement and market access. These require an increasingly holistic view of the healthcare world.'