The church, which opened in 1906, was sold by the Dunedin Diocese to a Naseby builder through a tendering process last month.
The Bishop of Dunedin, Colin Campbell, will formally decommission the church on March 8 after a final 4pm Mass.
Naseby historian Pat Shea said the church's last event would be open to all, and former parishioners would attend, including one who recently left the Maniototo for a post at Riverton.
Mr Shea said despite there being a sense of loss within Naseby as the church was sold, its new owner was known in the village for his quality restoration work.
Naseby builder Phil Flanagan purchased the building for its historic qualities, and wants to retain that character.
"I love the architecture of old churches, so the immediate plan is to protect the building.
The outside is protected and from the street there will be no visible changes, but although the inside isn't protected, I think it's so beautiful I want to retain every single feature," he said.
One of three churches in Naseby, the Catholic church followed two other churches built on site, in 1866 and 1874.
Former altar boy Gerald Dowling had to learn Latin when he started participating in Mass at the church in 1947.
Mr Dowling, who farms near Ranfurly, said his grandparents were married at the church, and his grandmother looked after the presbytery nearby.
Naseby resident Josie Dick said many people in the village did not want the church to be sold, but a decision to do so was strategic.
"It needed about $30,000 spent on it for maintenance and to get it up to scratch.
The Dunedin Diocese recognised there was another Catholic church just 10 minutes up the road, at Ranfurly," she said.
A rateable value of $136,000 was put on the Naseby church, although it sold for a "greater" amount, Mrs Dick said.
