Who is currently the Chief Justice of the United States?

The Chief Justice of the United States is John Roberts, who has held this position since September 29, 2005. As Chief Justice, Roberts plays a critical role in overseeing the operations of the Supreme Court and in presiding over oral arguments and court proceedings. His influence extends to the shaping of legal interpretation through his votes and opinions in important cases.

Ruth Bader Ginsburg, who is not currently serving, was a prominent figure on the Supreme Court until her passing in September 2020. Clarence Thomas is a long-standing Associate Justice but does not hold the position of Chief Justice. Sonia Sotomayor is also an Associate Justice appointed in 2009 and does not serve as Chief Justice. Therefore, John Roberts is the correct answer, reflecting both his role and tenure as the head of the United States judicial system.