Sibling rivalry! The younger step-brother of David Cassidy found fame of his own about 5 years after David's fame began to wane.

Shaun was cast as Joe Hardy in the Hardy Boys TV show and just like his brother, found himself in the record making business.

The younger Cassidy's first hit came in the Summer of 1977. His re-make of the 60's hit "Da Do Ron Ron" went to number one in short order.  He followed that with two more hits spaced only a few months apart. First with "That's Rock and Roll" and "Hey Deanie" . His hit record career lasted less than one year. Still, he had millions of fans and he is still remembered fondly.

So...what has he done since?

Since his "Teen Idol" years, Cassidy concentrated on stage acting for most of the 1980s and early 1990s. He appeared in Broadway and West End productions such as Mass Appeal, Bus Stop (in London) and Blood Brothers with half-brother David for over a year on Broadway. From the late 1990s, he concentrated on television production with credits such as American Gothic (with Sam Raimi), Roar, Cold Case, The Agency, Invasion and Ruby & The Rockits.

Cassidy has been married three times:

  • Ann Pennington (born 1950), a model; she and Cassidy married in 1979 and divorced in 1993. From this marriage Cassidy has a daughter, Caitlin (born November 25, 1981); a son, Jake ( born February 27, 1985); and a stepdaughter, Jessica Ann Wilson Kruse (born July 8, 1970).
  • Susan Diol, an actress, whom he married in 1995 and divorced in 2003. They have one daughter, Juliet (born March 19, 1998).
  • Tracey Lynne Turner, a producer, whom he married in 2004. They have four children: Caleb (born March 3, 2005), Roan (born September 23, 2006), Lila (born December 13, 2008), and Mairin (born June 25, 2011).