Turing was a brilliant logician who developed an electromechanical device called the Bombe, a code-breaking machine to decipher Nazi Enigma codes during WWII.
Although his war time work contributed greatly to Allied success, he was convicted of homosexuality in 1952. He chose to be chemically castrated in lieu of prison, and killed himself two years later at the age of 41 by eating an apple laced with cyanide.
"A pardon from the Queen is a fitting tribute to an exceptional man," British Justice Secretary Chris Grayling said in a statement Tuesday.
"Dr. Turing deserves to be remembered and recognized for his fantastic contribution to the war effort and his legacy to science."
British Prime Minister David Cameron hailed Turing as "a remarkable man who played a key role in saving this country in World War II by cracking the German enigma code."
The pardon went into effect Tuesday.