Natural Resources Canada says the epicenter was in Hawkesbury, Ont., 100 km east of Ottawa, across the river from Quebec.
The ministry had earlier said the quake was a 4.7-magnitude tremor centred around Lachute, Que., 50 kilometers northwest of Montreal.
The quake struck at 1:36 p.m. and was felt for about 15 seconds. There were no immediate reports of injuries or damage.