Born in 1949, Ann M. Veneman was raised on a peach ranch in California's San Joaquin Valley. While in high school, she served as a page at the Republican National Convention. In the 1960s, during her studies at the University of California at Davis, she served as an intern for then-Assemblyman Pete Wilson, another moderate Republican.

After graduating with a degree in political science, Veneman went on to earn a master's degree in public policy from the University of California at Berkeley. She then completed her legal studies by graduating from the University of California, Hastings College of Law. She also served as deputy public defender in Stanislaus County and as an attorney for the Bay Area Rapid Transit system. Veneman relocated to Washington in 1986 and worked for the United States Department of Agriculture's foreign agricultural service. She became the Agricultural Department's highest ranking woman to date when she was elevated to deputy undersecretary for international affairs and commodity programs in 1989.

From 1991 to 1993, she served in the administration of George H.W. Bush as the Department of Agriculture's deputy secretary. Veneman then worked at the Washington, D.C., law firm of Patton Boggs LLP, before moving to Sacramento to work with the law firm of Nossaman, Guthner, Knox & Elliott. She also served as a board member on the biotechnology company, Calgene, Inc., which produced the world's first genetically engineered food. When her former boss, Pete Wilson, was elected governor of California in 1995, he appointed Veneman California's secretary of food and agriculture; she won the support of farmers by laboring to open new foreign markets and taking steps against pests.

Her subsequent nomination to head the Department of Agriculture was reflective of her loyalty to George W. Bush: in 1999, Veneman was one of six California Republicans named to his California exploratory committee, and at the Republican National Convention in 2000, she sat on the national steering committee of Farmers and Ranchers for Bush.

Veneman announced her resignation after the 2004 election. Bush nominated Nebraska Governor Mike Johanns to succeed Veneman.