Harvard Law School (HLS) is the law school of Harvard University in Cambridge, Massachusetts. Founded in 1817, it is the oldest continuously operating law school in the United States and one of the most prestigious in the world.

Each class in the three-year JD program has approximately 560 students, among the largest of the top 150 ranked law schools in the United States. The first-year class is broken into seven sections of approximately 80 students, who take most first-year classes together. Harvard's uniquely large class size and prestige have led the law school to graduate a great many distinguished alumni in the judiciary, government, and the business world.

According to Harvard Law's 2020 ABA-required disclosures, 99% of 2019 graduates passed the Bar exam. The school's graduates accounted for more than one-quarter of all Supreme Court clerks between 2000 and 2010, more than any other law school in the United States.

Harvard Law School's founding is traditionally linked to the funding of Harvard's first professorship in law, paid for from a bequest from the estate of Isaac Royall Jr., a colonial American landowner and slaveholder. Today, HLS is home to the largest academic law library in the world as well as 391 faculty members.