TORONTO — Crime rates across Ontario continue to vary widely by region, with smaller and mid-sized cities consistently reporting higher severity levels than the province’s largest urban centres, according to recent data.Using the Crime Severity Index (CSI) — a national metric that measures both the volume and seriousness of police-reported crime — the following 10 communities rank among Ontario’s highest in overall crime levels..1. Thunder BayThunder Bay continues to post the highest crime severity scores in Ontario and among the highest in Canada. The northwestern city has struggled with elevated rates of violent crime in particular.2. Greater SudburyGreater Sudbury regularly ranks near the top of Ontario’s CSI standings, reflecting persistent challenges with both violent and non-violent offences.3. Sault Ste. MarieSault Ste. Marie has one of the province’s highest combined rates of violent and property crime, placing it consistently among Ontario’s most affected communities.4. BrantfordBrantford’s crime severity index remains well above the provincial average, driven largely by property-related offences and drug-related incidents.5. WindsorDespite relatively low homicide rates, Windsor continues to record elevated overall crime severity compared to many Ontario municipalities.6. LondonLondon remains one of the higher-ranking large cities in Ontario for crime severity, with increases in certain categories in recent years.7. HamiltonHamilton’s crime levels sit above those of many neighbouring communities, reflecting a mix of urban challenges and organized crime concerns.8. OshawaOshawa stands out within the Greater Toronto Area as having comparatively higher crime severity, particularly in property crime categories.9. Niagara Region (including St. Catharines)Communities across the Niagara Region report moderate-to-high crime severity levels, with St. Catharines often cited as a focal point.10. Waterloo Region (Kitchener–Cambridge–Waterloo)The Waterloo Region has emerged as one of Ontario’s higher-ranking areas for crime severity, reflecting growth-related pressures and urbanization..Broader trendsData show a consistent pattern: northern and mid-sized industrial cities tend to report higher crime severity than larger metropolitan centres such as Toronto. Analysts often point to economic disparities, housing pressures and access to services as contributing factors.While these communities rank highest within Ontario, overall crime levels across the province remain relatively low by international standards.