The urban center is located in the western part of the city about 10 kilometers inland from the coast.

The entire area of the Koshikijima Islands, in the East China Sea about 40 kilometers west of the mainland, is also included in the boundaries of Satsumasendai.

Satsumasendai has a mayor-council form of government with a directly elected mayor and a unicameral city council of 26 members.

In terms of national politics, the city is part of the Kagoshima 3rd district of the lower house of the Diet of Japan.

The city is also home to Kagoshima Immaculate Heart University, founded in 1994, which has a small population of foreign students.