Jack Black explained why people call him that even though it's not his real name

After appearing in films such as School of Rock, Tropic Thunder and The Holiday, as well as being one half of satirical rock duo Tenacious D, Jack Black is arguably one of the most recognisable names in Hollywood.

However, he hasn't always been known as Jack Black, with actor actually preferring to go by a different name to the one written on his birth certificate.

Using a stage name isn't unusual in Hollywood, with everybody from Marilyn Monroe, to Demi Moore, Calvin Harris and many, many more having some sort of stage name.

So what's the deal with Jack Black, and how close is it to his birth name?

Well it's not actually that different, with the 55-year-old explaining the story behind his birth name during an interview with The Howard Stern Show back in 2009.

What do you mean Jack Black isn't actually called 'Jack Black'? (Karwai Tang/WireImage)

Black is very much the actor's surname, however is first name is actually a nickname.

"I was always Black but I was not always Jack," he explained. "My legal name is Thomas Jacob Black. Jack was my nickname, my dad and mom called me Jack."

Going on to explain that naming a son 'Thomas' was somewhat of a tradition in his family, the Kung Fu Panda star continued: ""There was history behind it. My dad's dad was Thomas and his dad. And it goes back to, like, the ancient Ireland blacksmiths. There was a Thomas Black.

"They knew I was Jack, and I resented it, and so I was like, I just am Jack."

And it would seem the actor felt the need to continue the tradition when naming his own son, adding: "Then I felt the pressure and I named my son Thomas.

"When push came to shove I couldn't break the chain. I call him Tommy. Tommy's also my favourite album. The Who's Tommy."

In all fairness, Jack Black is much more memorable than Thomas Black (Jeff Hahne/Getty Images)

So there you have it, actor and Tenacious D rocker Jack Black is actually Thomas Jacob Black, but he seems to like going by Jack, so that's what we'll stick with.

As we mentioned earlier, Black isn't the only celebrity to use a name which is different to the one on their birth certificate.

For example: Brad Pitt is actually William Bradley Pitt, with the actor reportedly using his birth name when introducing himself, while Emma Stone was born with the slightly different name of Emily.

And Michael Douglas has to go by Michael Keaton, because there was already a Michael Douglas.