Tobias Augustus Matthay (19 February 1858 – 15 December 1945) was an English pianist, teacher, and composer. Matthay was born in Clapham, Surrey, in 1858 to parents who had come from northern Germany and eventually became naturalised British subjects. He studied composition at the Royal Academy of Music under Sir William Sterndale Bennett and Arthur Sullivan, and piano with William Dorrell and Walter Macfarren. He served as a sub-professor there from 1876-1880, and became an assistant professor of pianoforte in 1880, before being promoted to professor in 1884. With Frederick Corder and John Blackwood McEwen, he co-founded the Society of British Composers in 1905. Matthay remained at the RAM until 1925, when he was forced to resign because McEwen—his former student who was then the Academy's Principal—publicly attacked his teaching.
In 1903, after over a decade of observation, analysis, and experimentation, he published The Act of Touch, an encyclopedic volume that influenced piano pedagogy throughout the English-speaking world. So many students were soon in quest of his insights that two years later he opened the Tobias Matthay Pianoforte School, first in Oxford Street, then in 1909 relocating to Wimpole Street, where it remained for the next 30 years. He soon became known for his teaching principles that stressed proper piano touch and analysis of arm movements. He wrote several additional books on piano technique that brought him international recognition, and in 1912 he published Musical Interpretation, a widely read book that analyzed the principles of effective musicianship. Many of his pupils went on to define a school of 20th century English pianism, including York Bowen, Myra Hess, Clifford Curzon, Moura Lympany, Eunice Norton, Lytle Powell, Irene Scharrer, Lilias Mackinnon, Guy Jonson, Vivian Langrish and Harriet Cohen. He was also the teacher of Canadian pianist Harry Dean, English composer Arnold Bax and English conductor Ernest Read. Matthay also composed a quantity of piano music but it is little known.
His wife Jessie née Kennedy, whom he married in 1893, was a sister of Marjory Kennedy-Fraser. She died in 1937.