Judd Alan Gregg (born February 14, 1947) is an American politician from New Hampshire, currently serving in the Senate. He is a member of the Republican Party, and was an attorney before entering politics.

Born in Nashua, New Hampshire, he is the son of Hugh Gregg, who was governor of the state from 1953 to 1955. Gregg graduated from Phillips Exeter Academy in 1965. He earned an A.B. from Columbia University in 1969, a J.D. in 1972 and an LL.M. in 1975, both from Boston University.
Gregg was elected to the United States House of Representatives in 1980. He was reelected in 1982, 1984 and 1986. He declined to run for reelection in 1988, and ran for governor instead. He won that election and served as Governor of New Hampshire from 1989 to 1993. He was reelected in 1990, New Hampshire being one of the few states which continues to give its governors two-year, rather than four-year, terms.
In 1992, he took another successful political risk, as he decided to run for the United States Senate instead of running for governor again, and won the election. Gregg has been a United States Senator since 1993. He was reelected in 1998 and is a candidate in the U.S. Senate election, 2004.
In October, 2003, the Senator's wife, Kathy Gregg was kidnapped during an attempted burglary at the couple's Fairfax County, Virginia home. Mrs. Gregg escaped harm after her captors forced her to drive to a local bank. Two days later , two suspects were arrested in New Jersey.
In 2004, news accounts reported that Gregg was serving as a stand-in for John Kerry in the debate practice sessions being held by President George W. Bush.