Weatherly was born in San Antonio, Texas. Her mother is a former Christian Dior model and her father was a member of the US Air Force stationed in San Antonio. When Weatherly was nine-years-old, her family moved to Sumter, South Carolina, where she spent the remainder of her childhood years.
Weatherly attended Sumter High School located in Sumter, South Carolina. She graduated in 1977. Afterwards, she took her studies to Clemson University where she majored in nursing.
While still in college, Weatherly entered the 1980 Miss South Carolina USA Pageant. She won and went on to represent her state at the 1980 Miss USA Pageant.
Weatherly famously won the interview, swimsuit and evening gown competitions at 1980 Miss USA Pageant. She was crowned Miss USA 1980 on May 15, 1980 at the Gulf Coast Convention Center located in Biloxi, Mississippi.
Weatherly then went on compete in the 29th annual Miss Universe Pageant. Competing against 68 other contestants, she again won the interview, swimsuit and evening gown competitions. On July 8, 1980 she was crowned Miss Universe 1980 at the Sejong Cultural Center located in Seoul, South Korea.
After crowning her successor, Weatherly went on to have a successful television career. She is best known for her role as Jill Riley on the television show, Baywatch. She also appeared on the reality show Oceanquest and the comedy film Police Academy 3: Back in Training.
In 1994, Weatherly married Chip Harris, the president of a biotech research company. The two are still married and have two children together.