In a message to staff and students this week the USP's senior management said starting on New Year's Day campus security will enforce the decision.
It said those who failed to comply with the new rule would be fined about $US24.
The university said the decision included a transition period so the necessary preparations such as signage could be in place by January, 2021.
However, the new rule excludes staff residences on campus.
Vice Chancellor Professor Pal Ahluwalia said the smoke-free university will apply to all its campuses and rented facilities where USP business is carried out.
Professor Ahluwalia said given the health and financial benefits of quitting smoking, he hoped to receive everyone's support to ensure the USP is smoke-free.
"The university will be a smoke-free zone," Professor Ahluwalia said. "You will not be able to smoke cigarettes on campus.
"It's a big campus and we have a lot of trees but if anybody's going to do this, they are going to get caught out. We're making the campus smoke-free."
In May, a university report attributed one-third of cancer deaths in Fiji to smoking.
It said smoking had caused about 80 percent of lung cancer and 30 percent of cancer deaths.
"Non-smokers are also in danger through passive smoke and are at risk for lung cancer and other respiratory problems," the report said.
The university research also suggested that only five percent of cancers were hereditary.
"That means that the non-inherited causes of cancer is dependent on the lifestyle that we choose, the foods that we consume and the level of physical activity we do," the report said.