"Corne will play an integral role in shaping our continued success and growth in this region," said ANZ regional director Jon McGettigan.
"His experience in cloud security, data and emerging technologies plays well into our future plans as a business, and his expertise will be invaluable to our local customers."
Mare has more than 15 years experience in network security.
Between times he worked in application and data security within Imperva's global solutions architecture.
Mare previously worked in a variety of security and network related roles at organisations including MTN, Accenture and the South African Futures Exchange.
Fortinet has hired 30 people locally this year, including Dale Nachman as country manager for Australia.