The short answer (if you are in a hurry)
For most first-time visitors, the best time to visit Canada is the second half of June through mid-September. The mountain highways are fully open, the Atlantic ferries are running, the patios are full, and almost every park, lodge, and outfitter is at peak operation. Pick this window if you want the country at its busiest and most photogenic.
For better light, smaller crowds, and roughly 20% lower prices, come in mid-September to mid-October — Canada's fall shoulder season. For a country that feels genuinely different from anywhere else on Earth, come in January and February for ski season, the northern lights, and frozen-waterfall hiking in Banff. Avoid early April and most of November: spring slush and pre-snow grey are the only two weeks of the year we will tell you to skip.
If you want the deeper version — month-by-month, region-by-region — read on. The right time depends entirely on what you want to do and which corner of the country you are flying into.

