Forever 21 is a chain of clothing retailers throughout the United States, Philippines, Canada, Singapore, Indonesia, Malaysia, United Arab Emirates, Jordan, Oman, Kuwait, Saudi Arabia, Bahrain, Thailand, South Korea, Puerto Rico, and Japan 2009 offering fashion and accessories for young women and men (teenagers). Most of the retailer's apparel is private label and made in the United States in Southern California, with the exception of their "Fabulous Finds", which are very cheap items imported from Vietnam. Forever 21 typically serves the same audience and competes with Urban Outfitters, American Eagle Outfitters, Wet Seal, Guess, and Charlotte Russe.

1984-1999

The chain, originally known as Fashion 21, was founded in Los Angeles, California in 1984 by Korean-American Do-Won Chang and his wife, Jin-Sook. The first store , located at 5637 N. Figueroa St. in the Highland Park district of Los Angeles was only ; it is still in operation and bears the chain's original name. By the end of the first year, sales had risen from $35,000 to $700,000. Fashion 21 eventually expanded at the rate of a new store every six months and changed the Fashion 21 brand name to Forever 21.

In 1989, Forever 21 opened its 11th store and first store located in a mall, at the Panorama Mall which is in Panorama City, CA. Forever 21 increased its presence by expanding the average size to per store. Since then, Forever 21 has been running specialty stores in major mall locations nationwide. In 1995, the company expanded their chain to Florida and opened a store in Miami's Mall of the Americas, this location was the first store outside of California. Adding new stores every six months, Forever 21 had reached a total of 40 stores by 1997.

Creating its own prototype store in Northridge Fashion Center, Forever 21 has employed its proprietary design concepts to all its stores since. By this time Forever 21 also increased its average size to per store in prime spots of top tier malls.

2000–2009

Drastically expanding the number of Forever 21 stores nationally, Forever 21 opened XXI flagship stores in Georgia, Texas, Miami, Los Angeles, Orem, Chicago, and Canada. The average size of XXI venues are average of . Since 2002, Forever 21 has been ranked as one of the 50 largest privately held companies in Los Angeles. In 2005, Forever 21 was operating over 355 locations nationwide with the brands Forever 21, XXI Forever, For Love 21, and Gadzooks. In September 2008, Forever 21 opened its new flagship store in North Atlanta, Georgia (Dunwoody), the first XXI flagship in Georgia. Another flagship opened in Atlanta two months later. Its numerous shop-in-shop concepts demonstrates the continuing strength of boutique and specialty retailing over the department or megastore format.

Forever 21 will open its first flagship store in Puerto Rico at Plaza Las Américas during Summer 2009. Forever 21 also has flagship locations in New York, San Francisco, and on the exclusive Michigan Avenue in Chicago. Forever 21 will be located in a 40,000-square feet space located in the third level of the mall, nearby the Food Court. The largest Forever 21 store to date is located in Calexico, California.