Lululemon Sues Costco for Allegedly Selling Knockoff Athleisure Apparel

July 1, 2025 — Vancouver / Los Angeles

Lululemon Athletica Inc. has filed a lawsuit against Costco Wholesale Corporation, accusing the retail giant of selling unauthorized copies of its popular athleisure apparel under Costco’s private label brands.

The lawsuit, filed on Friday in the U.S. District Court for the Central District of California, claims that Costco is infringing on Lululemon’s design patents and trade dress protections. According to the filing, Costco has been selling “knockoff” versions of Lululemon’s best-selling products, including its ABC line of pants, Define jackets, and Scuba hoodies.

“Costco has unlawfully traded upon Lululemon’s reputation, goodwill and sweat equity by selling unauthorized and unlicensed apparel employing knockoff, infringing versions of Lululemon’s well-known trade dress and design patents,” the complaint states.

Lululemon alleges that the imitation products closely resemble its designs in terms of appearance, stitching, materials, and branding approach, potentially confusing customers into believing the items are authentic or licensed by the company.

The lawsuit also highlights media coverage and widespread social media attention around so-called “Lululemon dupes” being sold at Costco stores across the United States. Articles from The Washington Post and The New York Times were cited in the court documents, with references to viral content on platforms like TikTok, where users promoted Kirkland brand products as affordable Lululemon alternatives.

In the New York Times article published in April, similarities between Lululemon’s ABC pants and Costco’s version were noted, although the review concluded that Lululemon’s offering was “more thoughtfully designed.”

Lululemon is seeking a permanent injunction to stop Costco from selling the allegedly infringing products. The company is also demanding monetary damages, though the exact amount has not been disclosed.

“We take the responsibility of protecting and enforcing our intellectual property rights very seriously and pursue the appropriate legal action when necessary,” a Lululemon spokesperson said in a statement to Reuters.

As of publication, Costco has not issued a public response to the lawsuit.

The legal action comes as Lululemon faces increased market competition and a slowdown in domestic sales. Analysts suggest the lawsuit could be a strategic effort to reinforce brand value and limit market erosion caused by lower-cost alternatives.

The case remains pending, and further court proceedings are expected in the coming weeks.