Deen J. Castronovo was born August 17, 1964 and is an accomplished drummer and singer, best known for being a member of Journey, Bad English, Wild Dogs, Revolution Saints and The Dead Daisies. He also has been a touring and studio member for Ozzy Osbourne, Steve Vai, Paul Rodgers and Black Sabbath's bassist Geezer Butler's GZR. While working with Wild Dogs, Deen met and began working with Tony MacAlpine, which lead to an introduction to future long-time collaboration partner, Neal Schon.

Shortly after, Neal would invite Deen to audition for a new band with Jonathan Cain, John Waite and Ricky Phillips, which became Bad English. After two albums, which included being nominated for Best New Group in 1989 at the International Rock Awards, Bad English disbanded in 1991. In 1995 a Greatest Hits was released.

Deen continued to be in various bands along with Schon, from Hardline to Paul Rodgers. After a 3-year stint with Vasco Rossi, he joined Journey, where he would spend the next 18 years and 5 albums as the lead drummer and an occasional lead vocalist. While not the original drummer for Journey, Deen has served as their drummer longer than anyone else to date.

In 2015 he was arrested after police say he physically injured a woman. As a result, he has been dropped from several upcoming Journey performances.

While still with Journey, Deen, Jack Blades, and Doug Aldrich formed Revolution Saints. The band, where Deen served as lead vocalist and handled drumming duties, released its self-titled debut album in 2015 and a followup in 2017.

In late 2017 Deen became the new drummer for The Dead Daisies. Deen and the band almost immediately began song writing and hit the studio, again with legendary producer Marti Frederiksen to record the 2018 album Burn it Down.

In 2020, Deen Castronovo joined the supergroup, Generation Radio. Deen plays drums and shares lead vocals with 2 times Grammy Award Winner Jay DeMarcus of Rascal Flatts, Jason Scheff, lead vocalist and bass player for the multi-platinum band Chicago , Chris Rodriguez and Tom Yankton.

In July 2021 Castronovo's returned to Journey as a second drummer alongside Narada Michael Walden.