Harry Andrew Blackmun (November 12, 1908 - March 4, 1999) was an Associate Justice of the Supreme Court of the United States from 1970 to 1994. He is particularly well-known as the author of the majority opinion in the 1973 Roe v. Wade lawsuit legalizing abortion in the United States.

Harry Blackmun was born in Nashville, Illinois, on the 12th of November, 1908. He graduated from Harvard Law School in 1932 and served in a variety of positions as private counsel, law clerk, and adjunct faculty at the University of Minnesota and the St. Paul College of Law. President Eisenhower appointed Blackmun to the United States Court of Appeals for the Eighth Circuit in 1959. In 1971 he was nominated for the Supreme Court by Richard Nixon and confirmed by the United States Senate in the same year.

At the time of nomination, he was generally expected to act as a conservative and narrow interpreter of the constitution. However, over time he turned into an independent-minded justice who supported both conservative and liberal positions, with an increasing weight on individual rights. In 1973 he penned the majority opinion in important lawsuit Roe v. Wade that struck down as unconstitutional state laws against abortion and to this day is basis for legal abortion in the United States. This made him highly unpopular and a target for sometimes extreme criticism among many American conservatives, despite the fact that he was a livelong Republican.

Harry Blackmun retired from the Supreme court in 1994 and died March 4th, 1999, from complications of surgery.