The United States Court of Appeals for the Second Circuit (in case citations, 2d Cir.) is one of the thirteen United States Courts of Appeals. Its territory covers the states of Connecticut, New York, and Vermont, and it has appellate jurisdiction over the U.S. district courts in the following federal judicial districts:

• District of Connecticut
• Eastern District of New York
• Northern District of New York
• Southern District of New York
• Western District of New York
• District of Vermont

The Second Circuit has its clerk's office and judges hear oral arguments at the Thurgood Marshall United States Courthouse at 40 Foley Square in Lower Manhattan. Due to renovations at that building, from 2006 until early 2013, the court temporarily relocated to the Daniel Patrick Moynihan United States Courthouse across Pearl Street from Foley Square; certain court offices temporarily relocated to the Woolworth Building at 233 Broadway.^[1]

Because the Second Circuit includes New York City, it has long been one of the largest and most influential American federal appellate courts, especially in matters of contract law, securities law, and antitrust law. In the 20th century, it came to be considered one of the two most prestigious federal appellate courts, along with the District of Columbia Circuit Court.^[2] Several notable judges have served on the Second Circuit, including three later named Associate Justices of the United States Supreme Court: John Marshall Harlan II, Thurgood Marshall, and Sonia Sotomayor. Judge Learned Hand served on the court from 1924 to 1961, as did his cousin, Augustus Noble Hand, from 1927 until 1953. Judge Henry Friendly served from 1959 to 1986.

• Daniel Patrick Moynihan United States Courthouse at 500 Pearl Street; the court's former temporary home
• Thurgood Marshall United States Courthouse at 40 Foley Square

As of August 10, 2023^[update]:

Chief judges have administrative responsibilities with respect to their circuits, and preside over any panel on which they serve, unless the circuit justice (the Supreme Court justice responsible for the circuit) is also on the panel. Unlike the Supreme Court, where one justice is specifically nominated to be chief, the office of chief judge rotates among the circuit judges.

To be chief, a judge must have been in active service on the court for at least one year, be under the age of 65, and have not previously served as chief judge. A vacancy is filled by the judge highest in seniority among the group of qualified judges, with seniority determined first by commission date, then by age. The chief judge serves for a term of seven years, or until age 70, whichever occurs first. If no judge qualifies to be chief, the youngest judge over the age of 65 who has served on the court for at least one year shall act as chief until another judge qualifies. If no judge has served on the court for more than a year, the most senior judge shall act as chief. Judges can forfeit or resign their chief judgeship or acting chief judgeship while retaining their active status as a circuit judge.^[8]

When the office was created in 1948, the chief judge was the longest-serving judge who had not elected to retire, on what has since 1958 been known as senior status, or declined to serve as chief judge. After August 6, 1959, judges could not become or remain chief after turning 70 years old. The current rules have been in operation since October 1, 1982.^[9]

The court has thirteen seats for active judges, numbered in the order in which they were initially filled. Judges who assume senior status enter a kind of retirement in which they remain on the bench but vacate their seats, thus allowing the U.S. President to appoint new judges to fill their seats.

• Judicial appointment history for United States federal courts#Second Circuit
• List of current United States circuit judges