Santa Catalina Island vs Catalina Island

Santa Catalina Island and Catalina Island both are nouns.

Word	Noun	Adjective	Verb	Adverb
Santa Catalina Island	Yes	No	No	No
Catalina Island	Yes	No	No	No

As nouns, Santa Catalina Island and Catalina Island are synonyms defined as:

Santa Catalina Island and Catalina Island: an island resort in the Pacific off the southwestern coast of California

Other synonyms of Santa Catalina Island include Santa Catalina.

Santa Catalina Island (noun)	Catalina Island (noun)
an island resort in the Pacific off the southwestern coast of California	an island resort in the Pacific off the southwestern coast of California