Which coffee chain has a green siren logo?

The coffee chain with the green siren logo is Starbucks.

Starbucks was founded in Seattle at Pike Place Market on March 30, 1971, by Jerry Baldwin, Zev Siegl, and Gordon Bowker. It initially sold roasted coffee beans and brewing equipment rather than operating primarily as the espresso-focused café chain associated with it today. Howard Schultz later helped transform the company into a large coffeehouse business.

The logo depicts a twin-tailed mermaid, described by Starbucks as a siren from Greek mythology. Its design has changed several times: the earliest version was brown and showed more of the figure, while later versions became more streamlined. Green became the dominant color in the 1987–1992 redesign and remains central to the brand.

A common mix-up is assuming the logo is simply a mermaid. “Siren” is the company’s preferred description, although scholars have debated the artwork's precise historical inspiration, including possible links to medieval or Renaissance imagery.