Dianne Kasnic was born in Economy, Pennsylvania, the daughter of Joseph J. Kasnic and Anna Mae Kosyrich Kasnic. Her father was a farmer, steelworker and coal miner. "My father always appreciated scientific things, even though he only went to the seventh grade," she explained in 1978. "We had a small farm and there were lots of chemicals around so I got interested in chemistry." She graduated from Ambridge Area High School in 1956, and the University of Pittsburgh in 1960. She earned a PhD in physics at Johns Hopkins University in 1967. Her dissertation was titled "Strength-half-width Products of Self-broadened Lines in the 6.3 Micron Band of Water Vapor".