Dunedin Christmas Charitable Trust is running the event, which takes place at the Dunedin Town Hall from 11.30am on Christmas Day.
In a statement, trustee Rob Riddell Tigeir said the dinner was completely free and everyone was welcome.
People can book online at www.christmas.org.nz/dinner-invite/booking-form, by phone on (03)471-6150 or in person by visiting the first floor of Dunedin Community House at 43 Princes St.
Mr Riddell Tigeir said the trust was also taking sign-ups for volunteer opportunities.
Volunteers were needed in the week before Christmas as well as on Christmas day, he said.
Examples of the roles included table hosts, waiters and waitresses, kitchen team, cleanup and pack-down crews on Christmas Day.
Opportunities in the week prior included the Town Hall setup, decorating and food preparation.
You need to be 14 or older to volunteer.
Those interested in volunteering can visit www.christmas.org.nz/volunteer-sign-up to sign up.
— APL