Thomas Attwood (23 November 1765 – 24 March 1838) was an English composer and organist.
The son of a musician in the royal band, Attwood was born in London, probably in Pimlico. At the age of nine he became a chorister in the Chapel Royal, where he received training in music from James Nares and Edmund Ayrton. In 1783 he was sent to study abroad at the expense of the Prince of Wales (afterwards George IV), who had been favourably impressed by his skill at the harpsichord. After two years in Naples, Attwood proceeded to Vienna, where he became a favourite pupil of Mozart. On his return to London in 1787 he held for a short time an appointment as one of the chamber musicians to the Prince of Wales.
In 1796 he was chosen as the organist of St Paul's Cathedral, and in the same year he was made composer of the Chapel Royal. His court connection was further confirmed by his appointment as musical instructor to the Duchess of York, and afterwards to the Princess of Wales. For the coronation of George IV. he composed the anthem I was Glad. The king, who had neglected him for some years on account of his connection with the Princess of Wales, now restored him to favour, and in 1821 appointed him organist to his private chapel at Brighton.
Soon after the institution of the Royal Academy of Music in 1823, Attwood was chosen to be one of the professors. He was also one of the original members of the Royal Philharmonic Society, founded in 1813. He wrote the anthem O Lord, Grant the King a Long Life, which was performed at the coronation of William IV, and he was composing a similar work for the coronation of Queen Victoria when he died at his house at 75 Cheyne Walk, Chelsea, on 24 March 1838.
Attwood's funeral took place at St Paul's Cathedral on 31 March 1838. He is buried in the Cathedral, in the crypt, under the organ.
Attwood's compositions, which show the influence of his teacher Mozart, are now largely forgotten except for a few short anthems. These include "O God who by the leading of a star", "Come, Holy Ghost", "Turn Thy face from my sins", and "Teach me, O Lord". He was himself the teacher of John Goss, Cipriani Potter and his godson Thomas Attwood Walmisley, and in his last years a friend of Mendelssohn.