The agency delivered the Hyundai FanDome, Muji’s 25th anniversary exhibition and the launch of Slum Britain for Channel 5 in 2016.
Catherine Borowski, Produce UK's managing director, said: "Neil’s combination of industry experience and technological insight, combined with his clear commercial nous and creativity made him our number one candidate."
In his new role, Mortimer will handle the agency’s brand and production work.
Mortimer’s previous client experience includes delivering the live-streamed gig over the Atlantic as part of the #flightdecks campaign for Virgin Atlantic and EE's involvement at Glastonbury in 2015 and 2016.
Mortimer said: "I’m delighted to be joining an incredibly creative, agile and award-winning team. I'm on a mission to quantify the effects of experiential, at the centre of which must be compelling live experiences that require ambitious minds and ground-breaking creative."