Haa Dhaalu Atoll is the code name based on the letters of the Maldivian alphabet commonly used to refer to the administrative division (known as "Atoll") officially known as South Thiladhunmathi Atoll (Maldivian: Thiladhunmathi Dhekunuburi) in the Maldives.

Thiladhunmathi Atoll was divided into northern and southern divisions on 21 May 1958, thus creating the South Thiladhunmathi Atoll administrative division.

The capital of South Thiladhunmathi Atoll was Nolhivaranfaru before it was moved to Kulhudhuffushi on May 6, 1992.

South Thiladhunmathi is linked by air with the Maldivian capital of Malé as there are two airports in the atoll.

As well as dhoani's are used for transportation of cargo and people between Malé.