Joseph A. Cannon was born 31 July 1949 in Salt Lake City, Utah, the oldest child of Adrian W. and Pauline Black Cannon. At age ten his family moved to Los Angeles, California. One of his most memorable experiences occurred when, at age fifteen, he accompanied his father and two younger brothers on a bicycle trek from Los Angeles to the World's Fair in New York City.

Cannon returned to Utah to attend Brigham Young University. Following his freshman year in 1969, he served a two-year LDS mission in Ireland, after which he returned to school, worked as a pollster, and eventually married Janeal Barney. He received his B.A. degree in political science, and in 1977 graduated cum laude from BYU's law school, where he was an editor of the law review.

Cannon served as a law clerk in Salt Lake City for Judge Aldon J. Anderson before accepting a position with the Washington, D.C., law office of Philadelphia's Morgan, Lewis & Bockius, and later with Andrews and Kurth, also located in Washington.

In 1981 he was appointed by President Ronald Reagan to the Environmental Protection Agency (EPA) where he was later confirmed by the U.S. Senate as assistant administrator for air and radiation. His duties involved implementation and enforcement of the national air policy mandated by the Clean Air Act. He was involved in research on global warming and on health problems related to gasoline. Cannon also played a significant role in the regulation which controls fine particulate matter in the atmosphere.

In 1985 Cannon left the EPA and took a position as a partner in the Washington, D.C., office of San Francisco's Pillsbury, Madison & Sutro, specializing in environmental law. While working for the firm Cannon became aware of Utah's failing Geneva Steel Company.

Cannon studied Geneva's situation in detail and decided to rescue the mill by persuading influential Utahns to assist in the purchase of the plant. Cannon was able to achieve a leverage buyout and reopened the plant in September 1987 with himself as company president.

Cannon was determined to spend the hundreds of millions of dollars necessary to transform Geneva into the most modern and environmentally sound steel mill in the nation. His efforts to balance environmentalism and industry were recognized when the EPA honored Cannon and Geneva with its Outstanding Achievement Award in 1991 for their commitment to the environment. Cannon also was named Entrepreneur of the Year 1987 by Utah Business Digest and Businessman of the Year 1988 by the Utah Manufacturers Association.

In 1991 Cannon resigned as chief executive officer at Geneva to pursue a seat in the U.S. Senate. He was defeated in the 1992 Republican primary election by Robert Bennett.