John A. Lynch Jr. (born October 21, 1938) is an American former Democratic Party politician from New Jersey, who served in the New Jersey Senate from 1982 to 2002, where he represented the 17th Legislative District, and was Senate President from 1990 to 1992.
He was also the 61st mayor of New Brunswick, from 1979 to 1991.
Lynch was born in New Brunswick in 1938, the son of John A. Lynch, Sr. and Evelyn Rooney. His father also served as both Mayor of New Brunswick and State Senator from Middlesex County (7th District). He attended the College of the Holy Cross and Georgetown University Law Center.
Lynch was chosen in December 1989 to serve as Senate President, a position he held until 1991, when Republicans took control of the Senate. In 1997, after an unsuccessful effort to regain Democratic Party control of the Senate, Lynch stepped down from his position as the Minority Leader.
Bob Smith was elected in November 2001 to fill the seat vacated after Lynch retired.
The U.S. Attorney's Office for the District of New Jersey began investigating Lynch in the mid-2000s for his business dealings. On September 15, 2006, Lynch pleaded guilty in the U.S. District Court on one count of mail fraud and one count of tax evasion for failing to report $150,000 in income received from a real estate transaction in 1999. On December 19, 2006, he was sentenced by Judge Stanley R. Chesler to three years and three months in prison, which he was required to begin serving by January 15, 2007. Lynch was also required to pay a $50,000 fine.