The festival was held in conjunction with the Otago Farmers Market.
Co-organiser Nick Holmes was delighted with the response to the market and festival.
"It's been awesome. We just wanted to celebrate the local produce and stuff and I think it has happened."
Festival stalls covered topics from beekeeping to solar water heating, and one invited people to "ask a scientist about climate change".
Free vegetable seedlings being given away by Students for Environmental Action proved popular.
Also announced at the festival were the Eco Hero Awards.
Ten people were recognised for their "huge contribution to Dunedin's sustainability journey", organiser Jinty MacTavish said.
Maureen Howard won the "Eco Hero Supreme" award for her adult community education on sustainable living practices.
Others to receive awards were: Scott Willis for his work with the Waitati Energy Project and the Blueskin Resilient Communities Trust; Jason Ross for encouraging people to grow food at home; Lala Frazer for her work with Save the Otago Peninsula and Waitati Edible Gardens; Hendrik Koch for work with the Shetland St Community Gardens; Nicola Bould for work with Bags Not and the Harbour Cycle Network; Francisca Griffin and Dallas Henley for work with the Port Chalmers Community Gardens; Michelle Ritchie for adult eduction in organic food production; and Steve Walker for the harbourside cycle network.
About 500 people gathered in front of the railway station at 1pm for a Dunedin 350 day photograph.
The event was one of more than 4000 held worldwide to encourage people to reduce carbon dioxide emissions to 350 parts per million - the atmospheric CO2 concentration some scientists say is necessary to halt global warming.
Earlier in the day, about 50 surfers paddled out at St Clair to form a circle to highlight the action day, and a skateboard competition was held from noon at the Thomas Burns skateboard park.
Churches throughout the city tolled their bells 350 times in support of the action day.
About 200 cyclists took part in the inaugural 350 Riders' Rally, which was led by Olympic mountain biker Kashi Leuchs and professional cyclists Anja McDonald and Justin Leov.
