When Anthony Mackie found out that Vanity Fair wanted him for the cover of its Hollywood issue, his initial reaction wasn’t entirely enthusiastic. In fact, it might be more accurately described as clueless.

“They were like, yo, Vanity Fair wants you for the cover,” he says. And I was like . . .” He pauses to make a high-pitched “mmm” sound that conveys his initial doubts about the whole thing. “I mean, all right. I don’t know what I’d wear. And then, the night it came out . . . I had no idea how many people read that magazine.”

That’s life right now for Mackie, the respected but largely under-the-radar actor who has been thrust into the media spotlight — and cast in higher-profile roles — ever since his performance as the no-nonsense Sgt. J.T. Sanborn in last year’s Oscar winner “The Hurt Locker.”

One minute he’s just trying to choose the right projects; the next, he’s wearing a designer tuxedo and sandwiched between Oscar nominee Jennifer Lawrence and a scantily glammed-up Olivia Wilde on one of the most desirable magazine covers a Hollywood player can hope to land.

“As an actor in this business,” says Mackie, 31, “you’re the last one to know how your stock has changed.”

By all appearances, the Anthony Mackie S&P 500 is rising steadily. After “The Hurt Locker,” he starred in the well-reviewed indie “Night Catches Us,” which prompted the New York Times’ A.O. Scott to refer to Mackie as “one of the most consistently interesting and surprising movie actors around.” Now he’s opposite Matt Damon in the sci-fi-meets-political-thriller “The Adjustment Bureau,” which opened Friday.

He has also wrapped production on Hugh Jackman’s “Real Steel,” a futuristic boxing drama out in October; “Bolden!,” in which he stars as legendary jazz cornetist Buddy Bolden (tentatively for release this year); and the Elizabeth Banks action flick “Man on a Ledge,” due out in 2012.

And he’s joined the cast of one of the blogosphere’s most hotly tracked projects, the adaptation of Seth Grahame-Smith’s novel “Abraham Lincoln: Vampire Hunter,” in which Mackie will play the vamp-slaying best friend of our 16th president. (Let’s just say it’s only partly historically accurate.)

“I think he’s the next Will Smith, myself,” says George Nolfi, the writer-director of “The Adjustment Bureau,” who cast Mackie as Harry, a reserved and guilt-ridden member of a shadowy group attempting to control the destiny of Damon’s congressman character. “He has an undiscovered ability to be incredibly funny and charismatic in that way that Will Smith has. He’s got great acting chops.”

All this flattery might cause another actor’s head to noticeably inflate. But the 31-year-old New Orleans native — who studied at Juilliard, got his start in theater and made his major-studio debut in “8 Mile” — appears to appreciate the attention without injecting it directly into his ego.

He has had to work hard for a decade to get where he is, building a resume that includes films with Spike Lee (“She Hate Me”) and Clint Eastwood (“Million Dollar Baby”), roles as Tupac Shakur (“Tupac”) and a drug dealer (“Half Nelson”), and the occasional trifle he’d probably rather forget. (See “The Man,” starring Razzie nominee Eugene Levy and Samuel L. Jackson. Or, on second thought, don’t.)

Mackie comes across as the sort of actor who treats his career like a marathon instead of a sprint, constantly analyzing shortcomings, then training to be better. For example, he says Harry’s secretive demeanor in “The Adjustment Bureau” appealed because it gave him the chance to hone his ability to play understated.

But as seriously as Mackie takes his work, there’s no denying his humor. The guy — who spent most of this interview slouching comfortably on a sofa in a D.C. hotel suite and looking low-key in jeans and an untucked button-down — is a cutup.

He says he’d really like to do a comedy. But instead of bugging his agent to snag a gig as the quirky sidekick in the next Will Ferrell vehicle, he — again, marathon, not sprint — opted to take comedy classes and sign on for a small role in the upcoming Anna Faris/Chris Pine rom-com “What’s Your Number?”

“I wanted to get my feet wet and see what it was like,” he says.

Clearly, if Mackie is starting to be perceived as an “It” guy, he isn’t necessarily playing the part. Instead of Los Angeles, he opts to live in New York, where, in his limited spare time, he recently managed to open his own bar in Brooklyn.

“All the parties and stuff are for people that are looking for stuff that I am not really interested in,” he says.

So what does Mackie look to do in the future? He wouldn’t mind being in a comic book movie. “I would love to jump off a building and have whiskers come out of my hands,” he says, although he points out that, when it comes to typical superheroes, “none of those dudes look like me.”

He also half-jokingly expresses interest in making a movie version of the ’70s sitcom “Sanford and Son.” “That’ll be a game-changer,” he says. “I’ll definitely be Spider-Man if I play Lamont.”

But ultimately, he seems pretty satisfied to continue hanging out right where he is:

“I’m very happy being number four on the call sheet, because I can make fun of people and enjoy craft services all day.”