What was J.R.R. Tolkien's full birth name, including his middle names?

J.R.R. Tolkien's full birth name was John Ronald Reuel Tolkien.

Tolkien was born John Ronald Reuel Tolkien on 3 January 1892 in Bloemfontein, in the Orange Free State, which is now part of South Africa. “J.R.R.” comes from John Ronald Reuel, while Tolkien is his family surname. He was usually known publicly as J. R. R. Tolkien.

His first name was John, but Ronald was the name commonly used by family and friends. Reuel was also a significant family name; Tolkien’s father was Arthur Reuel Tolkien. Tolkien spent part of his early childhood in South Africa before his mother, Mabel, moved with him and his brother to England.

The name is sometimes misremembered as John Robert Tolkien because “R.R.” is often expanded incorrectly. The correct middle names are Ronald and Reuel, not Robert or Rupert.