Q:

Can a 13 year old boy marry a 18+ girl 

A:

You should abide by the laws of the land in such matters It is my understanding that many countries, including Canada, do not allow marriage under the age of eighteen. If you are sixteen and want to get married, you can do so in some provinces with your parents’ consent.

Islam teaches to abide by the laws of the land, for such rules are intended to safeguard the parties’ interests.

The age difference between boys and girls cannot be a deterrent as long as they fulfill the above requirements. Remember, the Prophet was 25 when he married Khadijah, who was forty, so the age differences should not be a reason to prevent the marriage.

Almighty Allah knows best.