And hubby, Pete Wentz, was just the guy to let us know.
"New blonde pixie haircut is cute," he tweeted. "I'll try and sneak a pic to post." He later followed with a photo of his bride and their young towhead blonde son, Bronx, adding, "Yah fam headed out tonight stoked! Cute hair mama!"
Glad to know he likes it. We like it too!
Ms. Simpson-Wentz is not the only Hollywood starlet to take the pixie plunge lately. She now joins the ranks of other short-haired stars like Kiera Knightley, Michelle Williams, Cate Blanchett and Emma Watson. She also rivals other platinum blondes like Katherine Heigl.
What do you think? Do you like Ashlee as a blonde, redhead or brunette?
At least we know her haircut is real -- unlike this celeb who faked us out!
Click here to see more celebs who switched up their 'dos for fall.