Big Bang: The most important scientific discovery of all time and why you need to know about it is a book written by Simon Singh and published in 2004 by Fourth Estate.

In parallel to the evolution of the Big Bang theory, the book tells the personal stories of the people who played a part in advancing it, both by hypothesis and by experiment.

These include Albert Einstein, for his General Relativity, Alexander Alexandrovich Friedman for first discovering that this theory led to an expanding universe, Georges Lemaître who concluded independently of Friedman discovered an expanding universe, and then that the theory must lead to an initial event of creation, which is the Big Bang theory we know today, Edwin Hubble for observing that the universe expanded, thereby confirming Friedman and Lemaître, George Gamow, Ralph Asher Alpher, Robert Herman, Martin Ryle, Arno Allan Penzias and Robert Woodrow Wilson, among many others.

William Grimes of The New York Times praised Singh's ability to retain the reader's entertainment and comprehension even whilst explaining difficult scientific concepts, through use of diagrams, writing and illustrations.

He wrote that, "[m]ore than the history of a single theory, [Big Bang] is an argument for the scientific method and for the illuminating power of human reason.