Leonard (Martin Landau)
Character Analysis
Leonard is Vandamm's yes-man, but since he refers at one point to his "woman's intuition", maybe we should call him the chief villain's yes-woman…?
This guy walks around with the most villainous leer imaginable. He's always watching.
And yes, it's as creepy as you're imagining.
Leonard's coded as gay not only because of this joking claim to women's intuition and his mannerisms ("his attitudes," in the screenplay's blunt words, are "unmistakably effeminate"), but also because he's "tellingly fashion-conscious," as theorist Lee Edelman writes.
In other words, in an age before the invention of the Metrosexual, Leonard's impeccable style was a dead giveaway. Plus, the association of gayness with villainy wasn't uncommon at the time when NXNW was made. Queers are murderous—and murderers are queer—in several other classics by Hitch himself, films like Strangers on a Train and Rope.
Here's what Martin Landau himself had to say about it:
I chose to play Leonard as a gay character. It was quite a big risk in cinema at the time. My logic was simply that he wanted to get rid of Eva Marie Saint with such a vengeance, so it made sense for him to be in love with his boss, Vandamm, played by James Mason. Every one of my friends thought I was crazy, but Hitchcock liked it. A good director makes a playground and allows you to play. (Source)
You may be thinking: wait. Isn't the clean-shaven, grey-suit-sporting Thornhill himself kind of a metrosexual avant la lettre? We hear ya. And that's why we suspect that Leonard's a foil for the film's hero.
Leonard falls to his richly deserved doom after trying one last time to kill Thornhill and Eve. Sadly, that ending spelled happiness to the straight America of 1959. The threat posed by Leonard's sexuality is eliminated, and in that way Thornhill's straightness is shored up, protected from the doubts that that beautifully tailored grey suit might raise, without Leonard there to take the fall.
Leonard's Timeline