Soisson was born in Auxerre. He was first elected to the National Assembly in the June 1968 parliamentary election and has been re-elected in every election since. He first entered the government when he became Secretary of State for Universities on 27 May 1974, serving in that position until 12 January 1976. He was Secretary of State near the Prime Minister, in charge of Vocational Training, from the latter date until 25 August 1976 and then Secretary of State near the Minister for Quality of Life, in charge of Youth and Sports, until 29 March 1977. He was Minister of Youth, Sports and Leisure from 5 April 1978 to 13 May 1981.
He returned to the government seven years later, becoming Minister of Labor, Employment and Vocational Training on 29 June 1988, in which position he served for three years before becoming Minister of State, Minister of the Civil Service and Administrative Modernization on 17 May 1991. He remained in that position until 29 March 1992. Later in that year he became Minister of Agriculture and Rural Development on 2 October, serving until 29 March 1993.
Soisson was Mayor of Auxerre from 14 March 1971 to 5 April 1998. He was also Vice-President of the General Council of Yonne from 1 January 1983 to 27 June 1988, then Vice-President of the Regional Council of Bourgogne from the latter date until becoming President in March 1992, in which position he served until 17 April 1993. He was again President of the Regional Council of Bourgogne from 16 March 1998 to 28 March 2004, and he remains a member of the Regional Council.
However, his alliance with the National Front between 1998 and 2004 in order to keep his seat in the Regional Council of Bourgogne tarred his career, and owed him to be excluded from the Union for French Democracy (UDF), along with Charles Baur, Jacques Blanc, Charles Millon and Bernard Harang. Soisson was finally beaten in 2004 by François Patriat.
Jean-Pierre Soisson is one of the French member of the National Assembly who hold the record for longevity by the number of terms, with Jean Tiberi and Didier Julia, 10 terms and 32 years in the Assembly since 1968. In 2011, he announced that he will not contested his seat again for the legislative elections of 2012.
Minister of Agriculture and Rural Development : 1992–1993.
Minister of State, Minister of Civil Service and Administrative Modernization : 1991–1992.
Minister of Labor, Employment and Training : 1988–1991.
Minister of Youth, Sport and Recreation : 1978–1981.
Secretary of State for Youth and Sports : 1976–1977.
Secretary of State for Vocational Training : January–August 1976.
Secretary of State for Universities : 1974–1976.
National Assembly of France
Member of the National Assembly of France for Yonne : 1968–1974 (Became secretary of State in 1974) / Reelected in 1978 but he became minister / 1981–1988 (Became minister in 1988) / Since 1993. Elected in 1968, reelected in 1973, 1978, 1981, 1986, 1988, 1993, 1997, 2002, 2007.
President of the Regional Council of Bourgogne : 1992–1993 (Resignation) / 1998–2004.
Vice-president of the Regional Council of Bourgogne : 1986–1992.
Regional councillor of Bourgogne : 1986–1993 (Resignation) / Since 1998. Reelected in 1992, 1998, 2004.
Vice-president of the General council of Yonne : 1983–1988.
Mayor of Auxerre : 1971–1998 (Resignation). Reelected in 1977, 1983, 1989, 1995.
Municipal councillor of Auxerre : 1971–1998 (Resignation). Reelected in 1977, 1983, 1989, 1995.