intro: At 49, Sandra Bullock tops the box office for a second week in a row in the space adventure "Gravity," defying Hollywood's former conventional wisdom that audiences won't go see an older woman in a leading role.
These days, actresses in their 40s are turning that convention on its head. Once relegated to supporting roles -- Sally Field famously played Tom Hanks' mother in "Forrest Gump" when she was 47 -- this latest crop of actresses in their 40s are now center stage.
"This is a great time for actresses over 40 -- maybe even a renaissance -- as audiences change and evolve," Paul Dergarabedian, a senior media analyst for global media research company Rentrak, told ABC News. "It's good for Hollywood, it's good for the audience and it's obviously great for these ladies."
It seems the 20- and 30-somethings who watched as Bullock's career blow up at age 30 as the star of the bomb-on-the-bus thriller "Speed" are still following her nearly 20 years later. Same goes for Julia Roberts, Jennifer Aniston, Halle Berry and Cameron Diaz.
"The 18-24 movie fans of 10 and 20 years ago are now in their 30s and 40s," Dergarabedian said. "They are still fans of the movies and they are growing up with the stars that they love. They are growing up together."
In fact, the Motion Picture Association of America found that more than one-third of all tickets purchased domestically in 2012 were by moviegoers age 40 or over. Baby boomers, who grew up going to the movies and account for 28 percent of the population, are certainly a big reason for the audience shift.
Not only are audiences rooting for these women with their dollars, but more of those dollars are landing in the pockets of these women, as top film actresses in their 40s out-earn their counterparts in their 30s.
Part of the reason is there are fewer shining stars in the generations that came after.
"There is a vacuum. Hollywood is not producing movie stars today like it did 20 years ago," Sharon Waxman, the founder and editor-in-chief of TheWrap, told ABC News. "And that leaves an opening for these women (in their 40s) from a business perspective as someone who has a built-in audience."
It also helps that some of these women look incredible.
"Forty is the new 25 in Hollywood," Waxman said. "We have these actresses who look incredible for any age. They have to appear on these screens in HD -- and 3-D in Bullock's case -- and they totally stand the test of the camera."
Click through to read more about five actresses in their 40s who are hot in Hollywood right now.
quicklist: title: Sandra Bullock text: "Gravity" is pretty much a one-woman show for Bullock, even with a weighty assist from George Clooney. Not only does she pull off an Oscar buzz-worthy performance but she flaunts her gravity-defying figure.
"She looks so amazing," Waxman said. "She told me that she worked really hard to look that good."
The Oscar-winning actress is having an incredible year, starring also in this summer's blockbuster buddy cop flick "The Heat," which grossed $226 million worldwide. media: 20602826
quicklist: title: Melissa McCarthy text: Bullock's "The Heat" co-star, Melissa McCarthy, not only doesn't appear to be your typical movie star, but she didn't break out until after 40.
After her hilarious supporting role in 2011's "Bridesmaids," McCarthy, 43, was cast opposite Jason Bateman in "Identity Thief," one of the year's top 10 grossing films. She followed up with "The Heat" and now finds herself in demand in Hollywood.
"Melissa McCarthy" is no one's idea of what a movie star looks like," Waxman said, "but she's so compelling, compulsively watchable and entertaining."
When Elle magazine, which features her on its November cover, is also under fire for having her appear in an oversize coat that covers most of her figure. media: 20603577
quicklist: title: Naomi Watts text: At 45, Naomi Watts believes her best days in Hollywood are still ahead.
"Women in their 40s have gone through quite a few different things, and so the roles are going to reflect that," she told Allure for its November issue. "People say, 'Oh, it's done by 40,' and now everyone knows it's not. I actually feel like the roles are a lot more interesting."
Watts plays Princess Diana in her latest film and was nominated for an Oscar for last year's "The Impossible." media: 20602898
quicklist: title: Cameron Diaz text: Cameron Diaz rose to fame in the 1990s in films such as "The Mask" and "There's Something About Mary." She was 28 when she first voiced the role of Princess Fiona in the "Shrek" movies. Now, at 41, she is the highest-paid actress among the over-40 set, according to The Hollywood Reporter. Diaz, who usually commands $15 million a film, negotiated first-dollar gross on her 2011 comedy "Bad Teacher" and netted $42 million. media: 20602750
quicklist: title: Robin Wright text: It used to be that actresses who had children "fell off the map" and returned to a shadow of their previous careers, Waxman said. Robin Wright, who has two children with ex Sean Penn, is an example of the new shift taking place for actresses in their 40s.
"I've never worked more than I have in the last few years," the 47-year-old told reporters at Cannes earlier this year. "We're navigating in different waters today. ... The industry is what shifted."
Wright, who starred in "The Princess Bride" and "Forrest Gump," is now earning some of the best reviews of the year -- and an Emmy nod -- as the unapologetically ambitious wife to Kevin Spacey's scheming congressman in the Netflix series "House of Cards." media: 20602428