She will take up her new role on 9 July 2018.
Johnson worked most recently at hospitality, tourism and sport fund Hostplus, where she was head of marketing and had previously held a number of senior marketing positions with brands including Pacific Brands and Crown Resorts.
MCEC chief executive Peter King said: “This is an exciting time for MCEC and I’m looking forward to Carolyn joining us.”
“It’s great to be a part of such a dynamic and progressive team, particularly at such an inspiring time in MCEC’s journey,” Johnson said.