He will work with PHD’s worldwide strategy and planning director, Mark Holden, on developing a global strategy and planning capability for the agency.
Devoy joins from Arena Media, where he was the digital planning director, as well as the head of its social media division, 247 Social.
Before that, Devoy spent seven years at i-level, where he worked as a planning associate.
Holden said: "Malcolm is going to be a great addition to the global team as he will bring data, digital and
social expertise in developing the global PHD planning product."
Devoy will work on global and international clients including SC Johnson, L’Oréal, Unilever and Kraft Foods, as well as the new clients Sony Ericsson and the hotel group Hyatt, which the agency won at the end of last year.