R. Paul Butler is an American astronomer, known as a pioneer in the search for and discovery of extrasolar planets. Working in close collaboration with Geoffrey Marcy, he developed and refined the technique of high-precision Doppler spectroscopy, a fundamental method for detecting planets by measuring the small gravitational wobbles they induce in their host stars. Their team was among the most prolific exoplanet hunters, contributing to the discovery of hundreds of new worlds. Their most significant achievements include the independent confirmation of 51 Pegasi b, the first planet discovered around a Sun-like star, and the identification of the first multi-planetary system around the star Upsilon Andromedae. For his groundbreaking work, conducted primarily at the Carnegie Institution for Science, Butler has received numerous international awards, including the Henry Draper Medal from the National Academy of Sciences and the prestigious Shaw Prize in Astronomy, considered the "Nobel of the East."