The son of William Hill, Thomas became a partner in the firm in 1856, the firm then becoming William Hill & Son. He worked in a conservative style, continuing firm's tradition set by his father but with a nod to the trends of the time. Features of his work were the greater use of string registers and an increase in the number of accompanimental and solo voices. The standard 3’ wind pressure was retained. He made a number of innovations on the mechanical side. Tubular pneumatic action was normal for large instruments by the mid 1880s, retaining the use of tracker action on smaller organs. He experimented with electric action and was responsible for the development of modern console design.

Organs representative of his work are:

• 1886: Sydney Town Hall—5-manuals, 127 stops, 45 ranks of mixtures, 64’ reed—the world’s largest organ at that time
• 1871: Manchester Cathedral (later rebuilt)
• 1874: Worcester Cathedral (later rebuilt)
• 1884: Westminster Abbey (later rebuilt)
• 1890: Birmingham Town Hall
• 1893: Peterborough Cathedral (later rebuilt)
• 1893: Queen’s Hall, London (destroyed by enemy action)