Until 1990, she lay buried in a small town called Faith, South Dakota in the US. When one day she was discovered by a woman named Sue.
The Field Museum of Chicago paid NZ$14 million for the fossil, which it keeps on permanent display.
It is one of two casts that travels the world. It weighs 1360kg and takes 56 hours to erect.
On Saturday, the Auckland Museum will lift the lid for people to come and marvel over the travelling exhibition that packs a punch.
The history of dinosaurs here in New Zealand is not so exciting because we do not have much to go on. Experts say there were four types once upon a time, but that is about it.
With Sue's fossil in the US, scientists have been able to learn all sorts of things. But not everything.