Bradford Parkinson (February 16, 1935) is an American engineer and inventor, retired United States Air Force Colonel and Emeritus Professor at Stanford University. He is best known as the lead architect, advocate and developer, with early contributions from Ivan Getting and Roger Easton, of the Air Force NAVSTAR program, better known as Global Positioning System. He was also the co-principal investigator (co-PI) and program manager on Gravity Probe B, which tested gravitomagnetism and was the first direct mechanical test of Einstein’s General Relativity.