Had his gall bladder removed.

Is good friends with Tim Robbins.

Starred in a management training film "Manager of the Year - Effective Listening (1987)" as a teenager who tells his father that the family car has been stolen.

Jack and his wife, Tanya Haden, became the parents of a boy, Samuel Wyatt, on June 10, 2006.

Auditioned for the role of "Cubby Barnes" in Ransom (1996).

Often competes for the same parts with Philip Seymour Hoffman. On the The School of Rock (2003) DVD audio commentary, he jokingly calls Hoffman "my nemesis."

Appears in a parody of the Council of Elrond scene shown during the MTV movie awards. Lord of the Rings director Peter Jackson later cast him in King Kong (2005).

His parents, who were both rocket scientists, divorced when Black was 10. His mother worked on the Hubble spacecraft.

Despite poking fun at the genre, he is actually a very knowledgeable fan of a lot hard rock/metal music from the 1970s and 1980s. He even appears as part of Tenacious D in the Ronnie James Dio video for the song "Push.".

Wife, Tanya Haden, is a cellist. She is the daughter of jazz great Charlie Haden.

One of his closest friends is David Grohl.

Is a member of, what the media refers to as the Frat Pack along with Will Ferrell, Ben Stiller, Vince Vaughn, Owen Wilson, Steve Carell and Luke Wilson. The Frat Pack name is a reference to the film Old School (2003), which features Vaughn, Ferrell, and Wilson, due to the wide number of films featuring the seven actors. Black's "Frat Pack" films include The Cable Guy (1996), Envy (2004), and Anchorman: The Legend of Ron Burgundy (2004).

Hosted the MTV Movie Awards in 2002 along with Sarah Michelle Gellar

Discovered he could act when he played a game of Freeze after a Passover seder.

Sang backup vocals for the songs in Bob Roberts (1992).

Originally met his wife in high school. They both attended Crossroads, a private school. They met again 15 years after they graduated high school at a friend's birthday party.

Revealed on an Australian late night variety show that his favorite KISS rock song is 1982's "I Love it Loud," where he began singing parodied lyrics to the first verse.

He and his wife eloped after dating less than a year. They were married in Big Sur, California by the same minister who performed Shane Stanley and Val Barri's ceremony in 2005.

Filmed a television pilot called Heat Vision and Jack (1999) (TV) co-starring Ron Silver, and Christine Taylor, and directed by Ben Stiller. The show was a parody of "Knight Rider" (1982), as well as other action/ adventure shows, and featured a talking motorcycle voiced by Owen Wilson.

Huge fan of Professional Wrestling.

Attended Poseidon School in Santa Monica, California.

Member of the band Tenacious D.

Born on the same day as Jason Priestley.

Good friends with Will Smith.

Jack and his wife Tanya are expecting their second child [2008].

His wife is a triplet. Her two other sisters, Petra Haden and Rachel Haden, also musicians, used to be members of the band That Dog. Petra was also a former member of the band The Decemberists. Their brother is Josh Haden.

Mentioned in the song "High School Never Ends" by Bowling for Soup, as "the clown".

Attended Crossroads High School for the Arts and Sciences.

Shares a birthday with Shania Twain, LeAnn Rimes and Daniel Stern.