Fashion trends, while often seen first on the runway, don't only begin and end on the catwalk. Often, trends are formed after a celebrity is simply seen out and about in an accessory, color combo or article of clothing that breaks the barriers of a norm.

Trends are also known to be replicated from popular television series or movies. 

Cher Horowitz, played by Alicia Silverstone in the 1995 rom-com "Clueless," secured the trend for plaid skirt and top sets.

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Sandy Olsson, played by Olivia Newton-John in the 1978 classic "Grease" set the tone for a black off-the-shoulder top and skintight, black pant combo.

Trends come and go, though, and some are here to stand the test of time. Read on for major fashion moments from iconic celebrities that have yet to go out of style.

Black and white photo of Audrey Hepburn as Holly Golightly in "Breakfast at Tiffany's"

Audrey Hepburn's little black dress was worn in the 1961 film, "Breakfast at Tiffany's." (Paramount Pictures/Getty Images)

  1. Princess Diana and street style
  2. Paris Hilton and velour tracksuits
  3. Jennifer Aniston's haircut in "Friends"
  4. Audrey Hepburn's black dress in "Breakfast at Tiffany's"
  5. Britney Spears and Justin Timberlake in denim on denim
  6. Jacqueline Kennedy's tailored suit sets

1. Princess Diana

It’s hard to choose just one monumental Princess Diana look that heavily influenced fashion, because the late royal set many trends. 

One of the most famous looks that transfers to today's fashion was her use of the well-tailored blazer. 

Princess Diana mixed casual and comfy with business chic by pairing jeans and T-shirts or crewnecks with large but structured blazers. This look stuck is a trend that is widely seen across the globe today.

In 1988, Princess Diana attended the Guards Polo Club in England. She wore denim, a white graphic crewneck and an oversized black blazer. She paired the ensemble with brown boots and a blue baseball cap. On paper the outfit choice doesn't scream ‘matching’ but on Princess Diana, it was well put together. Thus, creating a trend.

Princess Diana wore biker shorts with oversized sweatshirts and sneakers, shades too big for her face, voluminous puffer jackets and pants that billowed around the knees. Each of these clothing commitments are why the world of fashion is still obsessed with Diana.

Princess Diana wearing a blazer, baseball cap and boots

Princess Diana had an influential fashion sense. One of her trendy outfits was her blazer look from 1988. (Tim Graham Photo Library via Getty Images)

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2. Paris Hilton and velour tracksuits  

Paris Hilton famously modeled Juicy Couture velour tracksuits in and around Beverly Hills and on her popular television series "The Simple Life." The fashion icon sported tracksuits, tennis shoes and big sunglasses for years and introduced it as a major trends in the consecutive years. 

In early 2022, Hilton launched her own line of tracksuits on her website. "Tracksuits have been iconic since the early 2000s and remain a staple in my wardrobe to this day," her site says.

3. Jennifer Aniston haircut in "Friends"

Jennifer Aniston, who played Rachel Green on the popular television series, "Friends," started a fashion trend simply with her haircut. 

The hairstyle, which is known as "The Rachel," was worn by the actress mainly during the first few seasons of the hit show. 

Jennifer Aniston as Rachel Green in "Friends"

Jennifer Aniston's hairstyle that she wore when playing Rachel Green in "Friends" at the start of the show has become an extremely popular look. (NBCU Photo Bank/NBCUniversal via Getty Images via Getty Images)

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The 90s look is a short haircut, just above the shoulders with light curtain bands and layering. While the cut itself is a trend, the blown out version is what sets it apart from another style.

4. Audrey Hepburn's black dress in "Breakfast at Tiffany's"

Audrey Hepburn was known for her glamorous style. Her iconic fashion choices included ball gowns, bold hairpieces and hats and often, she was seen wearing gloves. 

In the classic film, "Breakfast at Tiffany’s," Hepburn wore a floor-length "little black dress" by French fashion designer, Hubert de Givenchy. The dress wasn't originally floor-length, though. Givenchy designed a shorter style which wasn't considered appropriate for the film and the bottom half was redesigned by Edith Head, according to hautehistory.com.

Since the release of the film, little black dresses are considered a staple item in women's closets. The famous look was paired with bold, pearl jewels and big, black sunglasses. 

5. Britney Spears and Justin Timberlake in denim on denim 

At the 2001 American Music Awards, then it-couple Britney Spears and Justin Timberlake appeared on the red carpet in matching denim outfits. 

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Britney Spears and Justin Timberlake wearing denim outfits at the American Music Awards

Denim on denim was worn by Britney Spears and Justin Timberlake during an American Music Awards appearance. ( Jeffrey Mayer/WireImage)

Spears wore a floor-length denim dress with a short train and accessorized with a denim bag and silver jewelry. Timberlake wore a denim jacket and jeans with and topped the look off with a denim cowboy hat.

6. Jacqueline Kennedy's tailored suit sets

Jacqueline Kennedy is considered one of the most elegant, glamorous FLOTUS' to date. 

The former first lady often appeared to events in simple, but tasteful attire. Her collection of black-tie attire memorable strapless dresses, gloves galore and tailored designer suit sets. She paired nearly everything with a bold headpiece, diamonds or pearls.

Jackie O paved the way for tailored suit sets and whether casual for work or seen on celebrities like Blake Lively, they are very readily worn today.