Bryce Seligman DeWitt (January 8, 1923 – September 23, 2004) was an American theoretical physicist. He studied gravity and field theories. He was awarded the Dirac Prize in 1987, the American Physical Society's Einstein Prize in 2005, and was a member of the National Academy of Sciences and the American Academy of Arts and Letters. DeWitt created the Wheeler–DeWitt equation for the wavefunction of the Universe with John Archibald Wheeler and advanced the formulation of the Hugh Everett's many-worlds interpretation of quantum mechanics.