Edwin Powell Hubble (November 29, 1889 – September 28, 1953) was an American astronomer. He profoundly changed our understanding of the universe by demonstrating the existence of other galaxies besides the Milky Way. He also discovered that the degree of redshift observed in light coming from a galaxy increased in proportion to the distance of that galaxy from the Milky Way. This became known as Hubble's law, and would help establish that the universe is expanding.

Edwin Hubble was born to an insurance executive in Marshfield, Missouri, and moved to Wheaton, Illinois, in 1889. In his younger days he was noted more for his athletic prowess than his intellectual abilities, although he did earn good grades in every subject except for spelling. He won seven first places and a third place in a single high school track & field meet in 1906. That year he also set the state high school record for the high jump in Illinois. Another of his personal interests was dry-fly fishing, and he practiced amateur boxing as well.

His studies at the University of Chicago concentrated on mathematics, astronomy, and philosophy, which led to a bachelor of science in 1910. Hubble also became a member of the Kappa Sigma Fraternity, and in 1948 was named the Kappa Sigma "Man of the Year". He spent the next three years as one of Oxford University's first Rhodes Scholars, where he originally studied jurisprudence, before switching his major to Spanish and earning his master's degree, after which he returned to the United States. Some of his acquired British mannerisms and dress stayed with him all his life, occasionally irritating his American colleagues.