Dave Baxter was awarded the APRA Silver Scroll and was nominated for three New Zealand Music awards.
Nomad is made up of Aasha Mallard, Will McGillivray and Cullen Kiesanowski who first formed a band when they were at school.
Their music has been described as alternate pop/folk.
The headline acts would be complimented by local bands as well as the popular Christmas at the Park Carols Band.
Among the local talent set to take the stage will be Critical Theory, a five-piece band from Napier Boy's High School who won the Smokefree HB Rockquest in June this year.
Covers band Groove Foundation will also be part of the planned four-and-a-half hours of stage entertainment.
"It is a great line-up of entertainment," Mr Trim said.
New to the event this year will be fairground rides, and while the concert event is free there will be charges for the rides.
There will be a free children's obstacle course and face-painting.
Mr Trim said the event would wrap up at 9.30pm with the traditional spectacular fireworks display.
"This is the perfect timing to then stroll next door and experience the Fiesta of Lights at the showgrounds - it will be an incredible night of fun."
Christmas in the Park has been running for 16 years and had previously been held at Anderson Park in Greenmeadows.
It is now staged as Hawke's Bay Christmas in the Park and will alternate between Hastings and Napier each year, with the Napier event expected to be staged at McLean Park in 2017.
"This is a not-for-profit, privately-organised event," Mr Trim said.
"It relies primarily on funding trusts and business sponsors to survive and we are so grateful to our financial backers who continue to support us every year in creating a true community event for Hawke's Bay, and we look forward to this new era for Hawke's Bay Christmas at the Park," he said.