Harvard Law School (also known as Harvard Law or HLS) is one of the professional graduate schools of Harvard University. Located in Cambridge, Massachusetts, Harvard Law is one of the most prestigious law schools in the world. It is also the United States' oldest law school in continuous operation. It is home to the largest academic law library in the world.

Harvard Law introduced what became the standard first-year curriculum for American law schools — including classes in contracts, property, torts, criminal law, and civil procedure — in the 1870s, under Dean Christopher Columbus Langdell. At Harvard, Langdell also developed the case method of teaching law, which became the dominant model for U.S. law schools.

The current dean of Harvard Law School is Elena Kagan, who succeeded Robert C. Clark in 2003.

The size of each cohort in the J.D. program numbers approximately 550 students and the first-year (1L) class is broken into seven small sections of approximately 80 students, who take all first-year classes (with the exception of one distribution requirement and one elective) together. Harvard Law has 246 faculty members.

Admission to Harvard Law is highly selective: For the class beginning in 2007-2008, 11.7% of 6984 applicants were admitted, and 67.9% of those admitted enrolled. The median half of the class that entered in 2007 had a GPA between 3.75 and 3.95 (out of 4.00) and an LSAT score between 170 and 175 (out of 180). Harvard Law's admissions process includes the unusual feature of telephone interviews conducted amongst students likely to be accepted.

Harvard Law School has produced numerous leaders in American law and politics, including many more U.S. Supreme Court justices and U.S. Senators than any other law school. In part because of its large size, it is consistently the best represented law school among the faculty at the U.S. law schools and among the attorneys at the top law firms in the U.S.