This is a bit tricky because there are actually two types of ounces in both Canada and the US:

* Fluid ounces (fl oz): This is the most common type of ounce used for measuring liquids.

* Weight ounces (oz): This is used for measuring weight.

Here's a breakdown:

Canadian Fluid Ounce:

* 1 Canadian fluid ounce = 29.5735 ml (exactly the same as the US fluid ounce)

US Fluid Ounce:

* 1 US fluid ounce = 29.5735 ml (exactly the same as the Canadian fluid ounce)

Important Note: While the fluid ounces are the same, weight ounces differ:

* 1 Canadian weight ounce = 28.3495 grams

* 1 US weight ounce = 28.3495 grams

So, in short, there are 29.5735 ml in both the Canadian and US fluid ounces.