McKay joins BlowUp Media from Clear Channel Outdoor where she spent 10 years.
She will be responsible for leading the UK sales team and driving business across its giant poster and digital out of home portfolio, reporting to managing director Dominic Gesua.
In her role as sales group head at Clear Channel, she managed sales across its Pinnacle premium format sites, as well as the group's reach and digital formats.
Prior to Clear Channel, McKay worked as a media consultant at Look Outdoor (now APN) in New Zealand, across its airport media portfolio.
Gesua said: "Aimee's knowledge, passion and wide-ranging experience are an ideal fit for this pivotal role.
"I look forward to working with her on the sales strategy, and continuing the fast pace of growth we are making in the UK."
BlowUp Media has a portfolio of 300 sites across Europe, mainly in Germany, the UK, Spain, Holland and Belgium.
Follow Nick Batten on Twitter @NickBatten2