A firstborn of Broadway entertainer Jack Cassidy's and actress Shirley Jones's three sons, Cassidy was inspired per profits of his half-stepbrother David Cassidy of the Partridge Family. He went to the equivalent senior high school when Angelina Jolie, Nicolas Cage, David Schwimmer and Lenny Kravitz.

He freed many successful singles in the late 1970s. His number 1 lone, the cover version of The Crystals "Da Do Ron Ron", hit #1 within the United States in 1977, & he, such as David, became the major teen idol. He achieved ii farther top 10 singles using cover of Eric Carmen's "That's Rock 'N' Roll" & "Hey Deanie" a equivalent month.

Cassidy starred paired Parker Stevenson in the popular Hardy Boys television series which ran for many seasons in ABC-TV starting in 1978. Cassidy processed his Broadway debut in 1993 in a production of Blood Brothers.

Cassidy has ventured into writing & producing. Among his credits come a hit CBS shows Cold Case and The Agency.

He has ii tikes by his 1st married woman, exemplary Ann Pennington, & of these infant by his 2nd married woman, actress Susan Diol. In August 28, 2004, he married his third wife, producer Tracey Turner by having whom he has 1 baby.