Absinthe, as you may imagine, has a very checkered history when it comes to the law.  And it is currently even more confusing, given its long dormant history and vast supplies of misinformation.  For instance, here in the US it is illegal to sell or import any drink that contains thujone, a key ingredient in absinthe that comes from the wormwood (Artemisia Absinthium) plant. Thujone is called a "known harmful" ingredient, so the FDA bans its use in food for human consumption, so you can't sell it, but you're allowed to buy, possess it and, yes, even drink it, because the FDA only goes after sellers, not buyers. 

But here's a good link with thumbnail sketches of absinthe's legality in many countries and areas around the world.  I have been reading some debate about its Canada entry, as even the officials there seem to be confused as to its real status, as opposed to its "I think..." status.