Appropriately for spring, the 24-year-old actress graces the front of the magazine with a flower in her naturally wavy golden locks, while inside she mixes up her styles, wearing her hair down or swept to the side and tied into a sweet braid.
Although Seyfried has worn her hair a variety of ways on the many red carpets she's stomped down, she tells InStyle she sides with wavy versus straight ("It's natural," she explains. "It means I spend less time doing my hair") and likes to complement her look with a touch of makeup.
"[I like] smoky eyes at night, and a nice little cat eye is really helpful," she says. "You want to look like yourself but not too naked."
For fans wanting to channel Seyfried's beauty routine, she says she prefers pink nail polish over red (it stains her nails too much!) but flip-flops on the issue when it comes to lipstick, opting for a deep crimson shade over a pale pink.
"It has a more traditional glamour," she says. "It's timeless."
Oddly enough, one of Seyfried's most beloved red carpet moments skewed more hip than classic.
"I wore this sequined Stella McCartney gunmetal gray dress. It just fit so well and slimmed me down. I felt really good."
When she's at home, however, it's all about being cool but comfortable. "My favorite thing that I wear all the time are all three of my Alexander Wang T-shirts in black, beige, and gray."
The most shocking thing Seyfried reveals in her interview? "I would chop [my hair] all off for a movie, but the role would have to be worth it."
Let's hope that role never comes along.
To see more of Seyfried's signature mane and read more of her hair-care tips, pick up the new issue of InStyle Hair on newsstands tomorrow.
Who do you think has the best hair in Hollywood? Let us know in a comment.
In related news, read about Seyfriend's "Mean Girls" co-star Lindsay Lohan's legal troubles.