What is the birth name of J.K. Rowling’s character Lord Voldemort?

Lord Voldemort’s birth name is Tom Marvolo Riddle.

The name is revealed in Harry Potter and the Chamber of Secrets, when Tom Riddle explains that he transformed the letters of his name into “I am Lord Voldemort.” In the British wording, the anagram works exactly as written: TOM MARVOLO RIDDLE becomes I AM LORD VOLDEMORT.

Tom Riddle was born to Merope Gaunt and Tom Riddle Sr. He attended Hogwarts and was placed in Slytherin. As an adult, he rejected his family name and created the identity Lord Voldemort, which he associated with fear, power, and the rejection of his Muggle ancestry.

The US edition changes the middle name to “Marvolo” as well, so the anagram remains identical. “You-Know-Who” and “He-Who-Must-Not-Be-Named” are titles or euphemisms, not his birth name.