Well, so I like this guy and he likes me. But he's 18 and I'm 13 and I'm really curious as if, we date, would it be illegal? :s We both live in Canada :3

Illegal, no.
Advisable, certainly not !!!

What does an ADULT have in common with a MINOR CHILD !!!
FIVE years is a HUGE gap at this age.

There are no laws governing dating, but any sexual activity between the two of you could land him in jail.

What do your parents think of this? They would have to approve or he can get in serioud trouble by defying them.

And as Ben said, An 18 yr old that is even considering a romantic relationship with a 13 yr old is sick. Most likely he is grooming you for sex. You should run from this person and tell your parents about it.

In many jurisdictions he could be arrested for statutory rape--you are too young to consent. Also red flag for a guy that age to like you--- trust me he probably can't handle girls his own age.

If your parents give you permission to date him, you can date. That means only dating, nothing sexual. If he kisses you, it's sexual, and that could land him in jail. So why would he want to date someone he can't even kiss, or hold hands with?

He's 18, an adult, you're 13, a child. What do you two have in common? Nothing! Even if you're mature for your age, or he's immature for his age, you have nothing in common at all. At this age 5 years may as well be 50. So what about you does he find desirable? Nothing good I'd bet.

Ask mom and dad what they think, and if they'll allow this. If you don't, he could go to jail for parental interference.

Please read this regarding Canada's "Age of Protection".

And yes, even kissing is considered a sexual act, if it involves a person under age, such as yourself.

http://www.justice.gc.ca/eng/rp-pr/other-autre/clp/faq.html