The festival runs from Monday until the following Sunday, and will include more than 50 events and discounts on a range of activities.
Wild Dunedin trustee Rachel Cooper said organisers wanted to get Dunedin residents to explore their city.
"Take the time to go outside and do the things you wouldn't usually have done.
"You don't have to go away or leave Dunedin to have a wonderful time,'' she said.
This year's theme is fresh water, and events emphasise the connectivity between the ice on the mountains and the rivers which flow through the region.
The main event is the Small Things, Big Stories competition on the 26th, in which speakers argue for the best wild "thing''.
There, University of Otago emeritus professor Sir Alan Mark will be presented with the Wild Hero Award for his fresh water work.
Other events include a full-moon walk at Aramoana, a Water of Leith expedition, a ride to the Sinclair Wetlands, and a free day at the Orokonui Ecosanctuary.