Susie Wilson grew up in Gonzales, Texas, but moved to San Jose in 1960 when IBM transferred her husband, Bob. In 1972, an environmentalist group encouraged Wilson to run for San Jose City Council. A newcomer to politics, Wilson was always interested in pursuing opportunities for women and minorities in government.

Prior to her election, she had served as president of the PTA and volunteered at the YWCA. While serving on the city council, Wilson completed her undergraduate degree in political science at San Jose State University. Wilson's popularity was due to her genuine interest in the issues and her ability to facilitate compromises.

In 1978, became the second woman to be elected to the board of supervisors. When she was joined by supervisors Lofgren and Morgan in 1980, women held the majority for the first time. Wilson was active on a variety of issues, ranging from the environment to the role of women in government to the functioning of county bureaucracy. Strongly supportive of maintaining open space, Wilson usually voted to limit growth but also worked to ensure that the housing needs of her constituents were met.

Wilson was also involved in issues concerning water quality and hazardous materials. In the mid-1980s, the groundwater supply of Wilson's south county district had become tainted by agricultural and industrial pollutants. Tricholorethylene and Freon 113 were discovered in drinking water wells near IBM in 1984. In response to these problems, Wilson was appointed chair of the Drinking Water Subcommittee.

Perhaps the most difficult period of Wilson's service was in 1982, when, because of tax-cutting Proposition 13, the county was forced to make large budget cuts. Though 1,000 employees were laid off, Wilson fought to maintain Valley Medical Center and social programs.

During her 12 years as supervisor, she protected Valley Med from budget cuts, helped it acquire properties that would later comprise a thriving hospital campus and cofounded the VMC foundation to raise money for life-saving equipment and other needs. And in 2008, Wilson campaigned for a successful $840 million bond measure that helped Valley Med keep its lights on and survive several years of economic austerity.

Leaving office in 1990, Wilson established Solutions by Wilson, a consulting business that helps people resolve political problems. From 1990-1993, Wilson chaired the local YWCA Capital Campaign, which raised $3 million for the construction a low-income apartment complex that is now named the Susie B. Wilson Residence in her honor. A short time before her passing in 2018, the Board of Supervisors named the Women and Children’s Center for Wilson at a ceremony with she and her family in attendance.