Father of Big Bang is a Catholic priest, Father Georges Lemaître.
According to the Big Bang theory, the expansion of the observable universe began with the explosion of a single particle at a definite point in time. This startling idea first appeared in scientific form in 1931, in a paper by Georges Lemaître, a Belgian cosmologist and Catholic priest. The theory, accepted by nearly all astronomers today, was a radical departure from scientific orthodoxy in the 1930s. Many astronomers at the time were still uncomfortable with the idea that the universe is expanding. That the entire observable universe of galaxies began with a bang seemed preposterous.
By 1930, other cosmologists, including Eddington, Willem de Sitter, and Einstein, had concluded that the static (non-evolving) models of the universe they had worked on for many years were unsatisfactory. Furthermore, Edwin Hubble, using the world’s largest telescope at Mt. Wilson in California, had shown that the distant galaxies all appeared to be receding from us at speeds proportional to their distances. It was at this point that Lemaître drew Eddington’s attention to his earlier work, in which he had derived and explained the relation between the distance and the recession velocity of galaxies. Eddington at once called the attention of other cosmologists to Lemaître’s 1927 paper and arranged for the publication of an English translation. Together with Hubble’s observations, Lemaître’s paper convinced the majority of astronomers that the universe was indeed expanding, and this revolutionized the study of cosmology.