He attended Leamington College and Rossall School, Fleetwood, Lancashire, between 1885 and 1889, then went to Balliol College, Oxford in 1889 to study theology, graduating with a Bachelor of Arts degree in 1894. While at Oxford, Byles converted to the Church of England and later, like his younger brother William had done before, to the Roman Catholic faith, taking the name Thomas.
From 1885 to 1889, he studied at Leamington College and Rossall School in Fleetwood, Lancashire. In 1889, he moved to Balliol College, Oxford to study theology. He earned his Bachelor of Arts degree in 1894. During his time at Oxford, Byles converted from the Church of England to Roman Catholicism, adopting the name Thomas.