Robert Thomas Bakker (born March 24, 1945) is an American paleontologist who has significantly reshaped modern theories about dinosaurs. He is particularly known for supporting the theory that some dinosaurs were endothermic (warm-blooded). Along with his mentor John Ostrom, Bakker helped initiate the ongoing "dinosaur renaissance" in paleontological studies, starting with his article "Dinosaur Renaissance" in the April 1975 issue of Scientific American.

Bakker's specialty lies in understanding the ecological context and behavior of dinosaurs. He has been a major proponent of the theory that dinosaurs were warm-blooded, intelligent, fast, and adaptable. In 1968, he published his first paper on dinosaur endothermy. His seminal work, The Dinosaur Heresies, published in 1986, revealed the first evidence of parental care at nesting sites for Allosaurus. He also provided evidence supporting Eldredge and Gould's theory of punctuated equilibrium in dinosaur populations.

Bakker currently serves as the Curator of Paleontology for the Houston Museum of Natural Science.