40 Highest Grossing Stars Under Age 40 (Part 2): The Top 20!

B.O. avg $69.3 million
Age 17
Lead roles 3
B.O. cume $207.9 million

We all knew Hannah Montana attracted legions of tweens, but when Cyrus dropped the blond wig and dance numbers for The Last Song ($63 million), she proved true box office viability.

* Figures as of Sept. 23, 2010 from films released before Sept. 1

B.O. avg $83.2 million
Age 20
Lead roles 12
B.O. cume $998.4 million

She's the actress every tween girl wants to be. But outside of the Twilight franchise, she has yet to assert herself as a box office draw. (The Runaways earned $3.6 million.)

B.O. avg $85.1 million
Age 27
Lead roles 12
B.O. cume $1 billion

Hathaway's performances run the gamut in style and genre, but she's a consistent box office draw in movies such as The Princess Diaries ($108.2 million), The Devil Wears Prada ($124.7 million), and this year's Alice in Wonderland ($334.2 million).

B.O. avg $88.7 million
Age 29
Lead roles 16
B.O. cume $1.4 billion

In addition to toplining the Star Wars prequels, Portman scored as a cue-ball-headed action heroine in V for Vendetta ($70.5 million).

B.O. avg $90.4 million
Age 31
Lead roles 4
B.O. cume $361.6 million

The former Grey's Anatomy star has emerged as a reliable comedic lead (Knocked Up, 27 Dresses, The Ugly Truth). Though last June's Killers underperformed, it still earned $47.1 million.

B.O. avg $90.6 million
Age 37
Lead roles 11
B.O. cume $996.4 million

Marsden rarely opens a movie by himself. But he has played his share of third-wheel roles in big hits (X-Men, Enchanted).

B.O. avg $91.4 million
Age 28
Lead roles 16
B.O. cume $1.5 billion

She played consummate girl next door Mary Jane in the first three Spider-Man films. Dunst's other biggest hits came from portraying schoolgirls in Bring It On ($68.4 million) and Mona Lisa Smile ($63.9 million).

B.O. avg $98.8 million
Age 35
Lead roles 6
B.O. cume $593 million

Switching between guy-oriented flicks (The Hangover) and female-skewing comedies (He's Just Not That Into You) has paid off for Cooper. So has that devious smile.

B.O. avg $98.8 million
Age 35
Lead roles 18
B.O. cume $1.8 billion

Much of DiCaprio's haul comes from that superliner of a film, Titanic, but he followed the megahit with well-chosen, high-grossing collaborations with an impressive roster of directors.

B.O. avg $100.2 million
Age 25
Lead roles 13
B.O. cume $1.3 billion

As Elizabeth Swann in the Pirates of the Caribbean franchise, Knightley swashbuckled her way to commercial success, but it was her take on another Elizabeth — Bennet, in 2005's Pride and Prejudice — that earned her an Oscar nom.

B.O. avg $107.3 million
Age 29
Lead roles 8
B.O. cume $858.2 million

He made his name as Darth Vader in the final two Star Wars prequels, but that's a tough act to follow. Grosses for films like Awake, Jumper, and Takers have been strong, but more earthbound.

B.O. avg $132.3 million
Age 32
Lead roles 9
B.O. cume $1.2 billion

She has sizable parts in two of the biggest sci-fi franchises in the universe right now — playing a Na'vi in Avatar and Uhura in Star Trek. All she needs to do next is connect with audiences beyond her Comic-Con base.

B.O. avg $138.2 million
Age 35
Lead roles 10
B.O. cume $1.4 billion

Maguire already had a pretty decent résume — Pleasantville, The Cider House Rules, Wonder Boys — before he started squirting webs out of his wrists. Post-Spidey, his clout has been less super: 2009's Brothers grossed $28.5 million.

B.O. avg $144.8 million
Age 24
Lead roles 9
B.O. cume $1.3 billion

Sure, the Transformers films make up half of his grosses, and Indiana Jones and the Kingdom of the Crystal Skull accounts for another big chunk ($317.1 million). But LaBeouf has also shown his appeal in thrillers like Disturbia ($80.2 million) and Eagle Eye ($101.4 million).

B.O. avg $155.8 million
Age 33
Lead roles 8
B.O. cume $1.2 billion

He burst onto the scene as an elf in the Lord of the Rings trilogy (not counted here, since he was a supporting player), then sailed into box office glory with the Pirates of the Caribbean movies. But outside of F/X-driven tentpoles, he's had some trouble. (Kingdom of Heaven and Elizabethtown were both duds.)

B.O. avg $161.8 million
Age 24
Lead roles 5
B.O. cume $809.2 million

Pattinson has shown his box office chops (and choppers) in the Twilight saga. In last spring's Remember Me ($19.1 million), though, he had considerably less bite.

B.O. avg $170.1 million
Age 12
Lead roles 2
B.O. cume $340.2 million

How will kids learn the value of a dollar unless they get a part-time job? For Will Smith's son, who starred with Dad in The Pursuit of Happyness, acting made more sense than mowing lawns. The Karate Kid earned $176.6 million, and a sequel is already in the works.

B.O. avg $186.6 million
Age 18
Lead roles 4
B.O. cume $746.5 million

Remember when he almost got replaced after the first Twilight movie? Then Lautner packed on 30 pounds and — voilà! — a career. His first post-Twilight film, the ensemble love story Valentine's Day, made $110.5 million.

B.O. avg $244.7 million
Age 21
Lead roles 7
B.O. cume $1.7 billion

Paint a lightning bolt on his forehead and he's unbeatable. The question will be whether Radcliffe can draw an audience once he graduates from Harry Potter. (The 2007 indie December Boys, his first starring role outside Hogwarts, was released on only 13 screens and grossed $51,000.)

B.O. avg $349.6 million
Age 34
Lead roles 3
B.O. cume $1 billion

Headlining the biggest hit in history is one reason he tops this list — Avatar accounts for two-thirds of his grosses. But Worthington also helped carry Clash of the Titans ($163.2 million) and Terminator Salvation ($125.3 million), making him a bankable choice for filmmakers seeking a thirtysomething leading man who knows his way around a greenscreen.

Check out numbers 40-21 in Part 1.

More from EW:
TV Recaps: Glee, Dancing With the Stars, more hot shows
Dancing With the Stars: Hidden gems of the week!
Psycho Killers: Vote in EW's Halloween Bracket Game!