Fitch Ratings says Ontario has demonstrated "the ability to exert considerable, ongoing expenditure restraint while instituting revenue changes as necessary to achieve its deficit reduction objectives."
However, it notes Ontario had an accumulated deficit equal to 157 per cent of operating revenues in fiscal 2015 due to slow revenue growth.
The Fitch rating on Tuesday follows Standard & Poor's move on Monday to lower Ontario's financial rating to A+ from AA-.
S&P cited the province's heavy debt burden and budgetary "underperformance" compared with peers in other jurisdictions for the downgrade.
Finance Minister Charles Sousa welcomed the Fitch rating, saying in a statement that it is "an expression of confidence" in the government's plan to eliminate the deficit by 2017-18 while investing in the economy to create jobs.