- Made his Broadway debut in 1969 in the notorious flop The Figs Are Falling. Returned to Broadway in 1982 with better results as a replacement for Joseph during the original run of Joseph and the Amazing Technicolor Dreamcoat.
- Starred with his then-stepmother Shirley Jones in The Partridge Family.
- Was the world's highest paid performer by age 21.
- Released his first solo album, Cherish, in 1972.
- Posed nude in the May 11, 1972, issue of Rolling Stone magazine.
- Daughter Katie Cassidy has covered his 1970 hit "I Think I Love You."
- Races and breeds thoroughbred horses with wife Sue Shifrin.
- Topped TV Guide's 2005 list of the 25 Greatest Teen Idols.
- Worked with his three brothers in 2009 on the ABC Family show Ruby & the Rockits (Patrick costarred; Shaun produced; Ryan was a set designer).
- Supports and speaks on behalf of the Alzheimer's Research & Prevention Foundation.
- 1978, Emmy — Outstanding Lead Actor for a Single Appearance in a Drama or Comedy Series: Nominee
- Katie Cassidy — Daughter
- Shaun Cassidy — Half Brother
- Sherry Benedon — Ex-significant Other
- Patrick Cassidy — Half Brother
- Sue Shifrin — Wife (separated)
- Meryl Tanz — Ex-wife
- Shirley Jones — Stepmother
- Evelyn Ward — Mother
- Ryan Cassidy — Half Brother
- Jack Cassidy — Father
- Beau Devin Cassidy — Son
- Kay Lenz — Ex-wife
Season 1, Episode 22
- Birth Name: David Bruce Cassidy
- Birth Place: New York, New York, United States
- Birthday: April 12, 1950, Aries
- Profession: Actor, Singer