Title: President (government title)
Content:  In the recently established Supreme Court of the United Kingdom, the most senior judge is called the president of the Supreme Court. The lady/lord president of the Court of Session is head of the judiciary in Scotland, and presiding judge (and Senator) of the College of Justice and Court of Session, as well as being Lady/Lord Justice General of Scotland and head of the High Court of Justiciary, the offices having been combined in 1784.
Title: Chief judge
Content:  A chief judge (also known as chief justice, presiding judge, president judge or administrative judge) is the highest-ranking or most senior member of a court or tribunal with more than one judge. The chief judge commonly presides over trials and hearings.
Title: President of the Supreme Court of the United Kingdom
Content:  The President of the Supreme Court of the United Kingdom is equivalent to the now-defunct position of Senior Lord of Appeal in Ordinary, also known as the Senior Law Lord, who was the highest ranking among the Lords of Appeal in Ordinary (the judges who exercised the judicial functions of the House of Lords). The President is not the most senior judge of the judiciary in England and Wales; that position belongs to the Lord Chief Justice. The current President is Robert Reed, since 13 January 2020.
Title: Supreme Court (Denmark)
Content:  There are 19 judges in the Supreme Court. One of the Supreme Court justices is president of the Supreme Court, appointed by the other judges. A judge is the chairman of the Appeals Permission Board and currently a judge is on leave to serve as a judge of the European Court of Justice in Luxembourg. The Judges of the Supreme Court, like other judges, are appointed by the Minister of Justice on the recommendation of the Independent Board of Judges. Judges shall be retired at the end of the month in which they reach the age of 70, as according to section 5 of the Civil Service Act.
Title: Supreme Court of Israel
Content:  In a case on which the President of the Supreme Court sits, the President is the Presiding Judge; in a case on which the Deputy President sits and the President does not sit, the Deputy President is the Presiding Judge; in any other case, the Judge with the greatest length of service is the Presiding Judge. The length of service, for this purpose, is calculated from the date of the appointment of the Judge to the Supreme Court.
Title: Judiciary of Kenya
Content:  The chief administrator of the Supreme Court is the Chief Justice, who is the President of the Supreme Court. One of his/her responsibilities is to come up with procedures for running the courts, as well as decisions on staffing and where new courts should be opened. Certain situations dictate that the Chief Justice appoint a judge or panel of judges to deal with a specific matter. The Deputy Chief Justice is the deputy president of the Supreme Court. The judges of the High Court and the Court of Appeal each elect a member to deal with administrative issues as well as represent them in the Judicial Service Commission. The Chief Registrar of the Supreme Court has the responsibility of being the chief administrator and accounting officer of the Judiciary. The Court of Appeal, High Court and Magistrate Court all have a Registrar to serve as administrator, record keeper and accounting officer in each of the courts.
Title: Judge
Content:  many other courts. The judges of the Supreme Court of the United States, and the judges of the supreme courts of several US states and other countries are called "justices". Justices of the Supreme Court of the United States and Justices of other courts are addressed as "Justice (name)". The Chief Justice of the United States is formally addressed as "Mr. or Madam Chief Justice" but also may be identified and addressed as "Chief Justice (name)". The justices of the supreme courts usually hold higher offices than any other judges in a jurisdiction, including a justice of the peace, a judge who holds 
Title: Chief Justice of Japan
Content:  The Chief Justice of Japan (最高裁判所長官) is the chief judge of the Supreme Court of Japan and is the head of the judicial branch of the Japanese government. The Chief Justice is ceremonially appointed by the Emperor of Japan after being nominated by the Cabinet; in practice, this is following the recommendation of the former Chief Justice.
Title: Chief judge
Content:  In the U.S. state of New York, the judge that presides over the state's highest court, the New York Court of Appeals, is titled the "chief judge". Similarly, their fellow jurists on that court are titled "judges", while jurists who sit on lower courts are titled "justices". This is the reverse of usage in other states, where jurists who sit on the state's highest court(s) are titled "justices" and those in lower courts are titled "judges".
Title: Supreme Court of Japan
Content:  is appealed. The Supreme Court also manages the operation, budget, and personnel of all of Japan's courts. Decisions are made by a regular Conference of the Justices in the Supreme Court and implemented by the Administration Bureau of the Supreme Court. The Chief Justice of the Supreme Court, through the office of the General Secretariat, also has extensive control over judicial personnel, including judges. This includes the ability to determine posts of judges, which has a significant impact on their careers and advancement opportunities. The Supreme Court also oversees the Legal Research and Training Institute, which prospective legal professionals who have passed the National Bar Examination are required to attend to receive practical training.

Question: what is the head judge of the supreme court called?
Answer: Chief Justice of the United States.