Invercargill City Mayor Nobby Clark is recovering in hospital after suffering a minor heart attack.

Clark was taken to Southland Hospital and stayed overnight as a precaution after the incident on 27 December, said the council.

Deputy mayor Tom Campbell said Clark was in good spirits and recovering well with no further incident overnight, but had been transferred to Dunedin Hospital for further tests on Thursday.

"We're all very grateful for the care and support provided by the hospital care teams and our thoughts are with mayor Clark and his family as we wish him a speedy recovery," Campbell said.

"The mayor and his family kindly request privacy while they focus on his recovery but I look forward to receiving more positive updates to share as they become available to me."

Clark won the mayoralty from long-time incumbent Tim Shadbolt in last year's local body election.