South Sikkim is a district located in the northeastern state of Sikkim in India. It is one of the four districts of Sikkim and is situated in the southern part of the state. The district shares its borders with the Indian state of West Bengal to the south and east, and with the districts of West Sikkim and East Sikkim within Sikkim.

South Sikkim is known for its picturesque landscapes, lush green valleys, and beautiful mountains. It is home to several popular tourist destinations, including the famous town of Namchi, which is the district headquarters.