Illegal at any age
Minimum age is 21
Minimum age is 20
Minimum age is 19
Minimum age is 18
Minimum age is 17
Minimum age is 16
No regulation/no age set
The smoking age is the minimum legal age required to purchase or use tobacco or cannabis products. Most countries have laws that forbid sale of tobacco products to persons younger than certain ages, usually the age of majority.
This article does not discuss laws that regulate electronic cigarettes.