Good question!
Considering, in North America that 43 U.S. states (Alabama, Alaska, Hawaii, Mississippi, Utah, Wyoming and Nevada do not have lottos*), all Canadian provinces, the District of Columbia, Mexico, Puerto Rico, and the U.S. Virgin Islands all run government-operated lotteries, and that elsewhere in the world official lottos exist in at least 100 countries (on every inhabited continent), the short answer is… a LOT!
The WLA alone lists 144 member lotteries.
The long answer, as of January 2013: about 166. They can be categorized as follows:
- Africa: ± 4
- North and South America: ± 76 (Many countries/states/provinces also participate in multi-jurisdictional lotteries)
- Asia: ± 25
- Australasia: ± 4
- Europe: ± 57 (Many countries also participate in EuroMillions, and other multi-jurisdictional lotteries)
We also list many of these lotteries in our handy Lotto Directory.
[Sources: Wikipedia, Wikipedia, Lottery Insider, World Lottery Association, NASPL]
*Alabama, Alaska, Hawaii, Mississippi, Nevada, Utah and Wyoming also do not participate in the multi-jurisdictional lotteries, Mega Millions and Powerball.