The two-stall unisex toilet is expected to cost $100,000 and will be paid for by money from the government’s tourism infrastructure fund.
Waitaki District Mayor Gary Kircher said the toilet was "much needed" as the beach became more popular.
The entrance was recently developed by the Department of Conservation and Te Rūnanga o Moeraki, the local rūnanga.
That had increased the popularity of the public entranceway, but there was still no public toilet on the site.
Having any recreational space without a toilet meant running the risk of people relieving themselves in public, Mr Kircher said.
Moeraki Boulders Cafe owner Scott Johnston said people used the cafe toilets regardless of whether they were paying customers or not, which the business had learnt to live with.
They also used the cafe rubbish bins.
Many tourists used the stairs beside the cafe to get down to the beach and take the short walk to the boulders. A donation was asked for to use the stairs, which worked through an honesty system.
"At the end of the day if they put the toilet in, it might take a bit of the load off us," Mr Johnston said.
There were once public toilets near the cafe, but they had been removed more than 15 years ago, he said.
