Yes you can, but you have to manually set it up to gain access. The method differs depending upon what technology you are using Netflix on (PC, PS3, XBOX 360). For PC you can simply use Google Chrome and search for Hola Unblocker. You can then install Hola Unblocker as an add on to Google Chrome and select to unblock Netflix from its list of programs. You then need only go to the Netflix website and you automatically gain access to American Netflix from Canada.
If you are using a PS3 or Xbox 360 you will need to go into your internet settings and change the DNS settings to an American IP which you can find on how to videos on Youtube. You will then have access to American Netflix when you launch the Netflix app. Occasionally however you will have to change to a new set of addresses as sometimes certain addresses will become blocked.