What is the population of the Sioux Indian tribe today?

As of recent estimates, the Sioux Indian tribe, which includes several federally recognized tribes such as the Oglala Lakota and the Standing Rock Sioux, has a combined population of approximately 170,000 members. The largest group, the Oglala Lakota, has about 40,000 members. Population figures can vary due to factors such as self-identification and enrollment policies, but these numbers reflect a significant presence of Sioux people today.