Triopha catalinae, commonly known as the sea clown triopha or sea clown, is a species of colorful sea slug called a nudibranch. Sea clowns are a shell-less marine, gastronomic mollusk in the taxonomic family Polyceridae.
The species' Latin name is named after Santa Catalina Island, California.
This species lives in the Western Pacific from Alaska to Mexico, and has also been found in Japan and South Korea.
This nudibranch grazes on bryozoans.