O'Neill is originally a Californian surf wear and surfboard brand started in 1952 by Jack O'Neill. It moved down the coast from San Francisco to Santa Cruz by the end of the decade. Jack is credited to have invented the wetsuit, his son Pat the leash on the surfboard. The company logo symbolizes a breaking surf wave. "O'NEILL" and the "Wave logo" are trademarks registered worldwide.

In May 2007 the ownership of the brand was sold to Logo International B.V. a private company headquartered in The Netherlands. The company produces wetsuits, performance water and snow sports inspired apparel for young adults, and lifestyle apparel. The products are distributed to 86 countries worldwide, some by licensed distributors. In the United States, the O'Neill clothing license is held by the La Jolla Group, a privately owned apparel company based in Irvine, CA. The O'Neill wetsuit business continues to be owned by the O'Neill family and is based in Santa Cruz, CA.

In 1996 O'Neill set up the O'Neill Sea Odyssey, a free, ocean-based program to educate young people about the marine environment. Over 100,000 children have participated in this program. O'Neill is involved in various other causes to help support the environment, such as through O'Neill Blue