Justin Trudeau knows what he's got ... clearly.

The Canadian P.M. posed for the cover of Delta Airlines Sky Mag ... the July issue.

The shot is perfectly framed ... making his crotch the centerpiece. It's a little Sharon Stone "Basic Instinct," a little Michelle Pfeiffer "Dangerous Minds."

By the way ... crotch aside, nice sox.

With Obama out of office, Trudeau has a clear path to the hottest leader in the world. There are really no challengers.