The trust's Otago-Southland area manager, Owen Graham, said the weight of community support for the Tokomairiro Presbyterian Church was staggering.
The number of submissions was about four times higher than any previous record, Mr Graham said.
"It really sends a message that the Milton community, and surrounding districts, love their heritage and want to recognise and protect it. Tokomairiro is an outstanding church - striking in appearance and of significant historical and social value."
Earlier this year, the trust had assessed the historic values and significance of the church for inclusion in the National Register of Historic Places.
About the same time, the Otago Daily Times revealed church owners feared the church might have to be permanently closed because of rising costs and a falling congregation.
Although the church was identified in the 1970s as being a place of historic significance, it was not formally transferred on to the national register when it was established.
The trust is now going through the process of formally including it on the register.
Submissions closed late last month, and Mr Graham said of the 450 received, an "incredible" 449 supported its recognition.
It is not clear who filed the only opposing submission.
All of the submissions will now be evaluated, and the trust will prepare recommendations for a final decision to be made by its board, probably in December.
The Tokomairiro church was designed by architect Robert Arthur Lawson, whose impressive body of work includes several 19th-century Dunedin landmarks, notably the Municipal Chambers and the Presbyterian First Church.
