Claude Elwood Shannon (April 30, 1916 - February 24, 2001)
According to Wikipedia, Shannon was "an American electrical engineer and mathematician, 'the father of information theory'.
"Shannon is famous for having founded information theory with one landmark paper published in 1948. But he is also credited with founding both digital computer and digital circuit design theory in 1937, when, as a 21-year-old master's student at MIT, he wrote a thesis demonstrating that electrical application of Boolean algebra could construct and resolve any logical, numerical relationship. It has been claimed that this was the most important master's thesis of all time."