Britney Spears Turns 40 — Take A Look At Her Best Fashion Moments Over The Years

The singer hit the milestone birthday on Thursday, December 2.

With a career spanning more than two decades, Spears has become a cultural and fashion icon.

Scroll down to see the Crossroad actress' best looks.

Spears wore a daring black dress with a slit across her torso to the 2016 VMAs. She paired the dress with simple black heels.

The "Toxic" singer wore a low-cut gray dress with silver sandals to the Teen Choice Awards in 2015. Her purple and teal hair added the perfect pop of color. She took home the Choice Style Icon Award that night, which was well-deserved!

Spears rocked black open-toe platform boots with a black t-shirt dress at the 2011 VMAs. Her smokey eyes completed the edgy look.

One of Spears' most iconic looks was the black lace Dolce & Gabbana dress she wore to the 2001 MTV VMAs. She later delivered her unforgettable performance of "I'm A Slave 4 U" where a snake wrapped itself around her body.

Spears looked pretty in pink at the 2002 American Music Awards. She paired her bold dress with matching sandals and a cross necklace.

Another one of Spears' most iconic looks was her black leather dress from the 2002 VMAs. The mom-of-two completed the look with lace fingerless gloves, knee-high strappy heels and a hat.

The blonde beauty looked radiant in a lace dress and white boots at the 2003 VMAs. Spears heavily accessorized — but each piece pulled the outfit together.

Spears wore a sultry black dress with a slit to the VMAs in 2000. True to early '00s style, she crimped her hair and added a choker.

Spears added a pop of blue to her purple tasselled dress at the 2000 Teen Choice Awards with a necklace and bracelet. She toned down the outfit with nude lace up heels.