WASHINGTON (AP) _ U.S. Circuit Court Judge Robert Heron Bork, whom President Reagan said Wednesday he will nominate to the Supreme Court, believes the courts have extended constitutional rights and federal authority beyond their proper bounds.

Bork, 60, is best known for his actions during the so-called ''Saturday Night Massacre'' at the height of the Watergate scandal in 1973, when he obeyed President Nixon's order to fire special Watergate prosecutor Archibald Cox after the Justice Department's top two officials resigned rather than do Nixon's bidding.

The former professor at Yale University's School of Law has assailed high court decisions on abortion, sexual freedom and many types of free expression, charging that ''when the court nationalizes morality, it strikes at federalism in a central way.''

In April 1982, Bork said Roe vs. Wade, the Supreme Court decision that legalized abortion, ''is a classic instance'' of the court imposing its morality on local jurisdictions.

He contended that abortion should be a matter for local control.

At the time, Bork said Reagan appointments to the Supreme Court could have an important effect on slowing the expansion of constitutionally protected rights, although it was impossible to tell how permanent the impact would be.

If ''the industry of non-interpretive review'' was not stopped, constitutional rights would continue to be expanded beyond their rightful bounds, he said.

''The judge who looks outside the Constitution always looks merely inside himself,'' he said in June 1982.

A trend in expanding the Constitution could lead to the ''naturalization of moral values'' and a ''gentrification of the Constitution'' reflecting only upper-middle class values, he said.

Reagan appointed Bork to the U.S. Circuit Court of Appeals for the District of Columbia in 1981 and he was confirmed in 1982.

During the Watergate scandal's ''Saturday Night Massacre'' on Oct. 20, 1973, Bork fired Cox, at Nixon's direction, after Attorney General Elliot Richardson and Deputy Attorney General William D. Ruckelshaus resigned rather than follow Nixon's order.

After the resignations, Bork assumed the attorney general's position because his job as solicitor general made him third in the line of succession at the Justice Department.

Richardson, who now practices law, said Tuesday in an interview with The New York Times that Bork acted honorably in the incident by obeying Nixon's order and then calling for a new special prosecutor.

''I had asked the legal counsel to check whether Nixon had the right to fire Cox,'' said Richardson, who had made a commitment to the Senate not to fire the special prosecutor.

''The legal counsel concluded that he did. Therefore, we thought Bork could do the right thing and deliver that message. Bork deserves a lot of credit for standing up to Nixon and telling him to appoint another special prosecutor.''

Leon Jaworski was named Cox's successor.

Senate Majority Leader Robert C. Byrd, D-W. Va., said in advance of Reagan' announcement that the nomination of Bork ''would be inviting problems'' because of his role in the Watergate scandal. However, when questioned about Bork's chances for approval, Byrd said he could be confirmed.

Born in Pittsburgh on March 1, 1927, Bork received his bachelor's degree from the University of Chicago in 1948 and his doctorate of law there in 1953. He then served as a research associate on a law and economics project at the university.

Bork served in the Marine Corps Reserve from 1945 to 1946 and from 1950 to 1952.

He practiced law briefly in New York, then returned to Chicago where he worked from 1955 to 1962 for the law firm of Kirkland, Ellis, Hodson, Chaffetz & Masters.

In 1962, he became an associate professor at Yale University's School of Law, moving up to full professor in 1965. At Yale, he was known as a prolific writer who contributed to law journals and magazines such as Fortune and The New Republic, where he wrote a pro-Nixon article in 1968.

He went on leave from Yale in 1973 to work for the Justice Department during the Nixon administration, and returned to Yale in 1975, serving as the school's Chancellor Kent Professor of Law from 1977 to 1979. He then was named Alexander M. Bickel Professor of Public Law, a title he held until 1981 when he left the school to join the Washington law firm of Kirkland & Ellis.

He married the former Claire Davidson on June 15, 1952 and they had three children, Robert, Charles and Ellen. His wife died in 1980, and he married the former Mary Ellen Pohl in 1982.

He is the author of ''The Antitrust Paradox: A Policy at War With Itself.''