Quiksilver (Boardriders, Inc.) is an Australian retail sporting brand, founded in Torquay, Australia, but now based in Huntington Beach, California. It is one of the world's largest brands of surfwear and other boardsport-related equipment. The company Quiksilver Inc. was renamed Boardriders Inc. in March 2017, making it the owner of Quiksilver, Roxy, and DC Shoes. In 2018 Boardriders acquired Billabong International Limited, gaining the Billabong, Element, Von Zipper, RVCA and XCEL brands. The brands’s logo, designed by founder Alan Green and John Law in 1973, was inspired by Japanese painter Hokusai's woodcut The Great Wave off Kanagawa It depicts a large wave with a mountain on a red background.

The brand also produces a line of apparel for young women, under the brand Roxy. The Roxy logo consists of two copies of the Quiksilver logo, one reflected, forming a heart. Another line of apparel for women is under the brand Quiksilver Women. As of 2013, the Quiksilver Inc. lost financially for six years and initiated a turnaround plan to resolve this. However, in September 2015 the company filed for bankruptcy. After emerging from bankruptcy in early 2016, the company once again became privately held with Oaktree Capital Management as the majority shareholder.

In 1990, Quiksilver launched its sister brand for young women, Roxy. The brand was shuttered after 1991 surf industry crash but revived by Bob McKnight and Danny Kwock in 1992, signing Lisa Andersen in 1993. It was differentiated from the main Quiksilver line "for fear it would damage the men's brand", according to Randy Hild, the company's senior vice president of marketing. Roxy was chosen because it sounded like a punk band or club (likely Roxy Music and The Roxy respectively), and is also the name of the daughters of both CEO Bob McKnight and founder Alan Green. About 30% of Quiksilver's sales come from the Roxy line.

Since inception, Roxy has grown to be the largest action sport fashion apparel company for young women. In addition to apparel, it now also produces accessories, homewares, hard goods (snow and surf), wetsuits, footwear, books and perfumes. It has sub-brands for its children's ranges, Roxy Girl and Teenie Wahine.

In the spring of 2013, the "DVF loves Roxy" collection was released as a one-time limited edition collaboration line of swim and beach wear as well as accessories.