Kerrigan, who has more than nine years of digital marketing experience, will replace outgoing creative director Matthew Maxwell, who leaves at the end of the month.
Maxwell will still be involved with Twentysix, in a consultancy capacity.
Gail Dudleston, managing director of Twentysix, said: "Ian has a huge reputation in the industry as a creative heavyweight, with first class credentials to back it up.
"His appointment will bolster our already award-winning department and take it to new heights."
He has creative credits for numerous worldwide brands, including Virgin Mobile, Procter & Gamble, COI, Oxfam, Sony Playstation and General Motors. He has also won industry awards from the Australian Writers & Art Directors Association, Cannes and BIMA.
This article was first published on brandrepublic.com