Invercargill Mayor Nobby Clark said it was an important role as Project 1225 was a major community project.
It aims to have a new Southland Museum and Art Gallery built by December 2025.
"With Nigel’s resignation, I am pleased to advise that I have appointed Cr Grant Dermody as the lead councillor on the museum project.
"This role will complement Grant's current role as chair of our finance and projects committee," Mr Clark said.
He also said he would soon consider Cr Dermody’s role on the Bluff Community Board, "to ensure his workloads are suitable".
Cr Dermody said he felt honoured to be given the role.
"There's a really good project team in place that has a good momentum. So my job is just to ensure that continues, and we get a really great outcome for the community and both Invercargill and the wider South."
He would work hard to ensure the new museum was interactive, with the "wow factor" and something for the community to be proud of.
"It needs to reflect our past, present and future and the need to reflect the different people that make up that.
"It needs to tell our story in a really engaging way," he said.
While he acknowledged the timeline was quite ambitious, he was confident they would make it.
"Well, projects always have costs and time challenges, right? But that's a good thing, because it brings discipline.
"Discipline around ... making decisions and making sure you've got the best information to make the decision at the time."
He said a project without discipline of time and costs would never get completed — so he was up to the challenge.
Cr Skelt resigned last week after documents showed he was the subject of a sexual harassment complaint from an 18-year-old female staff member before his departure as manager of ILT Stadium Southland last month.
Cr Dermody has a good finance background, which included time in the banking sector when he was part of the SBS Bank executive team, and he works in the farming sector.
Last week, a team of architects from Fjcstudio, together with Auckland firms Evatt Martin and Design Tribe, were part of a meet and greet with the community.
While they said during the discussion that they had not started designing the building yet, they promised it would be something innovative and iconic.
