Pacific Sunwear of California, Inc. , branded as PacSun , is a United States-based retail clothing brand rooted in the youth oriented culture and lifestyle of California. The company sells lifestyle apparel, along with footwear and accessories designed for teens and young adults. As of late 2011, the company operated over 800 stores in all 50 states and Puerto Rico. PacSun is headquartered in Anaheim, California and operates a distribution center in Olathe, Kansas. The company's regional directors, district managers and store positions are located throughout the United States and Puerto Rico.  The company went bankrupt in April 2016 and is now owned by Golden Gate Capital. 
Initially founded by Jack Hopkins in 1980 as small surf shop in Newport Beach, CA,  the company offers products for both men and women that include: jeans, tees, tanks, polos, knits, flannels, hoodies, boardshorts, bikinis, shorts, pants, dresses, rompers, skirts, sweaters, jackets, snow apparel, shoes, sandals and accessories. As of April 2016, PacSun had 583 stores. 
PacSun built its business selling merchandise from established surf brands such as Quiksilver, Hurley, O'Neill, Billabong and Roxy but has long since expanded to include skate and street wear labels like Volcom, Vans, Converse, RVCA, DC Shoes, WESC, Nike, Diamond Supply Co., Young & Reckless, and Enjoi plus many more. Additionally, PacSun has been producing and selling apparel and accessories under proprietary brand names titled Bullhead Denim Co., Bullhead Black, On The Byas, Nollie, Kirra, Check & Stripe and Sound & Matter.
In 2009, Gary Schoenfeld became the CEO of PacSun. In 2017, Schoenfeld left PacSun and was replaced by James Gulmi. 
In May 2011, PacSun launched its first national advertising campaign called 'Dress Irresponsibly'. The highlight of the campaign included television commercials aired across a variety of networks that featured famous athletes from the brands they work with. Appearances by Rob Machado, Bucky Lasek, Chris Pfanner, Kelia Moniz, Ryan Dungey and Leo Romero, were significant in helping re-establish the brand among its male audience. Other elements of the campaign included print media in both endemic and fashion publications, and a digital engagement initiative on Facebook titled 'Dress Irresponsibly: Style Challenge.' Through a customized Facebook app fans were encouraged to upload photos of themselves that met weekly style challenges in exchange for a chance to win a styling gig at Nylon in New York City.
Following the launch of the Dress Irresponsibly campaign, PacSun continued to evolve from just a surf and skate apparel shop into a leading retailer of emerging brands, particularly for women. Collaborations with notable design minded labels Whitley Kros and LnA coupled with a turn to style and fashion focused garments has given the brand an elevated look.
In an attempt to connect to the company's California roots, the brand launched a national digital and print initiative titled Golden State of Mind. Golden State of Mind, or GSOM for short, is about celebrating the creativity and diversity of California and its people. Working with photographers Nicholas Maggio, Harper Smith and Andrew Kuykendall, PacSun has looked to capture the beauty and imagination of California through lifestyle imagery from such places as Lake Arrowhead, Los Angeles, Malibu, Pismo Beach, Big Sur, and San Francisco. As part of the initiative, the retail giant created a lifestyle content website called GSOM.com. The site includes an interactive experience containing: campaign imagery and videos, landscape photography, a series of city videos that highlight the best places and locations in California, an interactive map, a user generated social media feed from Instagram, and a blog focused on: fashion, music, art, entertainment, action sports and brands.
On February 23, 2005, the company restated results for certain periods to correct its accounting for leases.