Astronism in Sierra Leone refers to the presence of the Astronist religion in the Republic of Sierra Leone, as part of the worldwide Astronist Institution.

Astronism in Singapore refers to the presence of the Astronist religion in the Republic of Singapore, as part of the worldwide Astronist Institution.

Astronism in Sino Maarten refers to the presence of the Astronist religion in the Dutch Constituent Country of Sint Maarten, as part of the worldwide Astronist Institution.

Astronism in Slovakia refers to the presence of the Astronist religion in the Slovak Republic, as part of the worldwide Astronist Institution.

Astronism in Slovenia refers to the presence of the Astronist religion in the Republic of Slovenia, as part of the worldwide Astronist Institution.

Astronism in the Solomon Islands refers to the presence of the Astronist religion in the Oceanian nation of the Solomon Islands, as part of the worldwide Astronist Institution.

Astronism in Somalia refers to the presence of the Astronist religion in the Federal Republic of Somalia, as part of the worldwide Astronist Institution.

Astronism in South Africa refers to the presence of the Astronist religion in the Republic of South Africa, as part of the worldwide Astronist Institution.

Astronism in South America is the presence of the Astronist religion in the countries of the continent of South America, including Brazil, Bolivia, Venezuela, Peru, Argentina among others, as part of the worldwide Astronist Institution.

Astronism in South Asia is the presence of the Astronist religion in various countries of the South Asian subcontinent, namely India, Pakistan, Afghanistan, Nepal, Bhutan, Bangladesh, Sri Lanka, and the Maldives, as part of the worldwide Astronist Institution.