The North would need an extra 14 to 36 police positions to bring it into line with ratios in the West and South respectively.
The North has 1.68 police positions per 1000 people, compared with 1.78 police positions in the South and 1.93 positions in the West.
The government has an operational target of 1120 officers across Tasmania.
Opposition police spokeswoman Elise Archer said the fact that the North was the most under-policed district was a "disgrace".
"As a result of Labor and the Greens, the entire state is under- policed and we need to restore frontline numbers in all regions, especially the North," she said.
"There will be more police overall, and per capita, under a majority Liberal government than Labor and the Greens."
Ms Archer said she would release more details closer to the election.
The revelation of low police ratios in the North comes after a sergeant said police felt "outnumbered" and resources were "strained" when officers were called to a rowdy party in Launceston last week.
About 200 people, including youths, were spilling out into Canning Street from a unit.
Many were drinking and behaving in an anti-social manner. Police made nine arrests.
Sergeant Ivan Radosavljevic, of the Northern Road and Public Order Services unit, attended the incident and said officers from "all over the district" were called to help.
But Launceston Inspector Michael Johnston said no country units were required to attend.
He said the country units were advised they might be needed, but ended up not being required.
"It's a business continuity thing for police," Inspector Johnston said.
He also responded to police union claims that Launceston Uniform Division had a minimum staffing level of about four constables and one supervisor each shift.
Inspector Johnston said there was "always more than that", with two supervisors a shift, while the number of constables varied according to operational needs.