Douglas Joseph Bennet Jr. was born in Orange, New Jersey, on June 23, 1938, to Douglas Joseph Bennet Sr. and Phoebe Benedict Bennet. The family settled in Lyme, Connecticut. Bennet Sr. (Wesleyan class of 1933) was a businessman, and he also engaged in civic service. He was active in the Connecticut Democratic party and worked as executive secretary for Chester Bowles, then-governor of Connecticut, from 1949 to 1951. Phoebe Bennet was a graduate of Mt. Holyoke College and the New York School of Social Work. She was on the board of trustees for the Mansfield Training School and helped to establish the Office of Mental Retardation in the Connecticut State Department of Health. She was also on the board of the League of Women Voters in Lyme and the Lyme Board of Education. Bennet, Jr. was the oldest of five children. He graduated from Lyme High School in June 1955.

In the fall of 1955, Douglas Bennet, Jr. entered Wesleyan University as a freshman, class of 1959. During his four undergraduate years he showed a developing interest in history, government and the Russian language. He was co-president of the fraternity Alpha Chi Rho and was active in the Wesleyan chapter's decision to withdraw from the national organization as a result of racial and religious intolerance on the part of the parent organization. Although he would later self-deprecatingly describe this exercise by saying, "This operation involved a great deal of organizing and correspondence, and was one of the most inconsequential exercises imaginable," it was emblematic of his strongly developed social conscience. Bennet went on to receive his M.A. in history from the University of California, Berkeley in 1960 and then moved to Cambridge, MA, to begin work on his Ph.D. at Harvard.

Bennet's dissertation, was competed in 1967. In the intervening years he had his first taste of international government work. Family friend and mentor Chester Bowles, who was then Ambassador to India, offered Bennet a position as his administrative assistant in New Delhi, India, in 1963. Bowles had been a member of the U.S. House of Representatives from Connecticut's second district from 1959 to 1961 and his vision and civic engagement were models for Bennet. Although Bennet had been thinking of going to Russia, he went instead to India, and spent two and a half years there. During that time he traveled extensively and wrote many speeches for Bowles and other administrators. He returned to Cambridge in January 1966 and finished his dissertation the following year.

With his experience as a speech writer, Bennet was able to land a job in Washington as speech writer for Vice President Hubert Humphrey. This was the beginning of almost 30 years in Washington, although his occupation was to change many times. Being a speech writer for Humphrey quickly swept Bennet into the heady and intense world of politics, especially when Humphrey ran for president in 1968. When Humphrey lost the election to Nixon, Bennet joined the staff of Thomas F. Eagleton, a senator from Missouri, in January 1969.

He worked for Eagleton as administrative assistant for the next four years. Bennet was active in the 1972 presidential election, in which Eagleton was a candidate for vice president, and helped to craft the Democratic platform that year. The controversy that broke in July regarding Eagleton's mental health gave Bennet on-the-ground training in crisis management. In April 1973, Bennet joined the staff of Abraham Ribicoff, the senator from his home state of Connecticut, again as administrative assistant. This was a short lived assignment as Bennet decided to make a run for the House of Representatives in 1974. His father, Bennet, Sr. ran for the same position in 1956. Bennet, Jr. did not win the primary and ceded the Democratic House nomination to Christopher Dodd.

In September 1974 Senator Edmund Muskie tapped him to be the first staff director of the newly formed Senate Budget Committee. Bennet held this post for the next two and a half years and it was his last in the legislative branch of government.

In 1977 Bennet reconnected with his 1960s roots in the State Department by becoming the Assistant Secretary of State for Congressional Relations. His two and a half years in this position gave him exposure to current foreign policy thinking. He traveled to Africa and China and was credited by President Carter for being instrumental in the signing of the Panama Canal Treaties in 1977. In July 1979 Carter nominated him to be administrator for the Agency for International Development (AID). Bennet held this post for the next year and a half until the 1980 election and the change of administration in January 1981. During his tenure at AID he traveled intensively, both nationally and internationally.

In January 1981 Bennet decided to spend much of that year at a slower pace, exploring his options and reconsidering his involvement with government. In December 1981 he accepted an offer by Chicago businessman, Richard J. Dennis, to be president of the Roosevelt Center for American Policy Studies, a think tank started and bankrolled by Dennis. The mission of this organization was to act as a "bridge between the public and policymakers. By increasing the public's store of unbiased information, by opening up our national debate to fresh thinking about long-term solutions, and by working directly with policy-makers, the Center aims to help Americans and their leaders make constructive and farsighted policy choices." As president, Bennet was well positioned to make the best use of his extensive administrative and foreign policy experience. He worked hard for the next year and a half to further the Center's mission and was blindsided by Dennis's decision in June of 1983 to remove him as president. Bennet resigned at the end of June and spent the summer investigating the possibility of creating his own think tank, but lack of funding prevented it. In December 1983 it was announced that he would be the next president of National Public Radio.

National Public Radio was having its own problems in the early 1980s, having nearly declared bankruptcy just before Bennet became president. Fresh from his disappointment at the Roosevelt Center and bringing his impressive administrative skills to bear, he quickly turned NPR around, injecting solvency and a new sense of energy. Bennet took up the banner of freedom of speech and the first amendment as enthusiastically as he had foreign policy.

The pull of the State Department was still strong, however. After a break with government and 10 successful years at NPR, Bennet was ready to re-engage with global issues as Assistant Secretary of State for International Organization Affairs in 1993. For the next two years he worked closely with the United Nations working to improve the standard of living worldwide as he had, off and on, for thirty years.

Bennet had always retained a strong affection for Wesleyan University, his alma mater. He had been on its board of trustees for three years, from 1972 to 1975. His father was an alumnus and two of his children were alumni. So, in 1995 when he was asked to serve as Wesleyan's president, he accepted. He was president for 12 years, from 1995 to 2007, at which time he retired from public service.