William Thomas Best (13 August 1826 – 10 May 1897) was an eminent English organist and composer, celebrated for his exceptional skill and contributions to organ music. Born in Carlisle, Cumberland, he was the son of a local solicitor. Despite his father's aspirations for him to become a civil engineer, Best's musical talent was evident from a young age. He received early lessons from the organist of Carlisle Cathedral and practiced diligently, becoming largely self-taught in organ performance.

At the age of fourteen, Best became the organist of a Baptist chapel in Liverpool, where he honed his skills on a rare pedal keyboard. By twenty, he had committed to a professional music career, securing positions such as the organist at the Church for the Blind in Liverpool and later at the Liverpool Philharmonic Society. His career included a stint in Spain and London, where he played at the Royal Panopticon and briefly at St. Martin's-in-the-Fields and Lincoln's Inn Chapel.

In 1855, Best was appointed the corporation organist at St George's Hall, Liverpool, a position he held for nearly forty years, becoming renowned for his performances and recitals. His reputation as a leading organist was cemented by his role in inaugurating new organs across the UK and his performances at the Handel festivals. Despite offers of knighthood and other honors, Best chose a civil list pension and continued his work until ill health led to his retirement in 1894. His legacy as a performer, composer, and teacher remains influential in the world of organ music.