Brachiosaurus is a genus of Brachiosauridae, a giant herbivorous dinosaur.

It lived in North America during the Late Jurassic period, about 154 to 150 million years ago. Fossils were found in Jurassic strata. This genus is one of the largest animals that ever lived on land. Brachiosaurus is one of the tallest, largest and heaviest herbivorous dinosaurs that appeared in the late Jurassic period.

Early Brachiosaurus fossils were only found in North America, but later two other species of Brachiosaurus were discovered in Europe and Africa.

The most notable feature of Brachiosaurus is that its forelimbs are longer than its hind limbs, which is very different from other giant herbivorous dinosaurs of the sauropod class. This makes people believe that Brachiosaurus walked with its neck raised high.