This article assesses whether a deterrence gap exists in the enforcement of the Ontario Employment Standards Act (ESA), which sets minimum conditions of employment in areas such as minimum wage, overtime pay and leaves. Drawing on a unique administrative data set, the article measures the use of deterrence in Ontario’s ESA enforcement regime against the role of deterrence within two influential models of enforcement: responsive regulation and strategic enforcement. The article finds that the use of deterrence is below its prescribed role in either model of enforcement. We conclude that there is a deterrence gap in Ontario.