William Thomas Lewis, 1st Baron Merthyr, known as Sir William Lewis, 1st Baronet, from 1896 to 1911, was a Welsh coal mining magnate.
- Occupation
- industrialist, politician
- Position held
- member of the House of Lords, High Sheriff of Brecknockshire
- Citizenship
- United Kingdom of Great Britain and Ireland
- Born
- August 5, 1837
- Died
- August 27, 1914
