Santa Catalina vs Santa Catalina Island

Santa Catalina and Santa Catalina Island both are nouns.

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

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

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

Other synonyms of Santa Catalina include Catalina Island.

Santa Catalina (noun)	Santa 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