Simaxis is a comune, or municipality, situated in the Province of Oristano within the Italian region of Sardinia. It is geographically positioned approximately 90 kilometres northwest of Cagliari and about 11 kilometres northeast of Oristano.
The town serves as a local administrative center located in the central-eastern portion of the island. Its location provides proximity to both the regional capital of Cagliari and the provincial seat of Oristano.