ObamaCare's individual and small-business insurance exchanges are designed to offer a range of choices to consumers, from cheaper to more expensive plans.
Lt. Gov. Mary Taylor (R) in a statement blamed the average increases on ObamaCare's requirement that plans provide a minimum level of coverage.
"Ohio has traditionally had a more competitive health insurance market than other states with a wider range of prices and choices," Taylor said.
"That level of diversity is essentially outlawed under ObamaCare, so Ohio's rates and premiums are going up significantly."
The average price of a premium on Ohio's individual market will rise from $236.29 per month this year to $332.58 next year, the department said.
The prices do not include federal subsidies that will be available to eligible exchange applicants.
In all, Ohio has approved 200 plans on the individual side and 184 plans on the small-group side for its exchange. The marketplace is technically being run by the federal government, however.
The healthcare law sets up bronze, silver, gold and platinum levels of coverage, which will correspond with a range of prices.
Ohio did not release the lowest and highest numbers on that range or the average price in each coverage category.
Speaker John Boehner (R-Ohio) called the figures "irrefutable evidence" that ObamaCare is driving up healthcare costs.
But one of the law's chief implementers, Marilyn Tavenner, argued Thursday that insurance rates are benefiting from the Affordable Care Act.
"We're very pleased," she said, citing a federal report that rates have been lower than expected in 11 states. "In the state-based exchanges, it's been a good-news story."
Tavenner runs the Centers for Medicare and Medicaid Services and is charged with rolling out the exchanges.
The Health and Human Services (HHS) Department also released a statement on the rates.
"We are consistently seeing in states across the country that premiums are lower than expected and we are confident that Ohio’s premiums will be affordable," said HHS spokeswoman Joanne Peters.
—This post was updated at 6:34 p.m. with HHS's statement.