What state is Adelaide in? A What state is Adelaide in? Category: TravelAdelaide is the capital of South Australia. It is also one of the world’s most livable cities and fifth largest city of Australia. The city is located at the foot of the Mount Lofty Ranges.Check out things to do in Adelaide, Cheap holiday destination Adelaide, South Australia. Leave a Reply Cancel replyCommentEnter your name or username to commentEnter your email address to commentEnter your website URL (optional) Save my name, email, and website in this browser for the next time I comment.