The structure of the government of South Dakota is based on that of the federal government, with three branches of government: executive, legislative, and judicial. The structure of the state government is laid out in the Constitution of South Dakota, the highest law in the state. The constitution may be amended either by a majority vote of both houses of the legislature, or by voter initiative.

The governor of South Dakota is the head of government of South Dakota. The governor is elected to a four-year term in even years when there is no presidential election. The current governor is Kristi Noem, a member of the Republican Party who took office on January 5, 2019.