Whilst serving the British Government and posted in Lucknow he became a friend of the local Nawab Saadat Ali Khan and was responsible for building a palace called Dilkusha Kothi on the banks of the Gomti near Lucknow. This palace stood for about fifty years until it was damaged in the Siege of Lucknow. The palace was a copy of the English Baroque stately home of Seaton Delaval Hall.He made his name in India where he was appointed a Major-Commander. He was made a baronet in 1808 with the recommendation of Lord Wellesley.

He served as ambassador to Persia from 1810 where he was involved with negotiating treaties principally with Persia and Russia. He was accompanied by his brother as secretary, Sir William Ouseley, who like Gore was a keen orientalist. (He was the first ambassador to Persia since Sir Dodmore Cotton was sent by Charles I). Nominally he was supporting the Shah of Persia (Fat?h Ali Shah Qajar). The most important was The Treaty of Gulistan: ???????????? ???????; ) which was prepared by the ambassador with the help of the British Foreign Office. The treaty confirmed the inclusion of modern day Azerbaijan, Daghestan and Eastern Georgia into the Russian Empire. This was agreed on 24 October 1813.

After his brother returned to England in 1813 to write, he left the next year, stopping off in St Petersburg. Whilst he was in Russia he was awarded the Grand Cordon of the Russian Order of St. Alexander Nevsky. He was also responsible for publishing an early translation of the New Testament into Persian. The translation had been made by a friend, the Reverend Henry Martyn, and Mirza Saiyad Ali Kahn. Martyn had died on his way back to England so Gore Ouseley had agreed to arrange publication of the manuscript. This he did in St Petersburg, carrying out the proof reading personally. This version was later refined and republished in Calcutta.

On his return to England in 1815, Ouseley was not made a peer as he had expected (and despite a recommendation). He did however arrange for some gifts of antiquities to be given to the British Museum.

Ouseley had taught himself Sanskrit, Arabic and Persian, and for enjoyment, he and his brother William advanced the study of Persia. William published a number of books, but those by Gore were not published until after his death.

In 1833, the family were living at Hall Barns, and he enjoyed gardening and building work as he had done in India. In 1835, he served as the High Sheriff of Buckinghamshire.

He became President of the Society for the Publication of the Oriental Texts in 1842 and he is credited with the society's publication of Gulistan of Sa'di by Sa'di, which had a translation by Francis Gladwin.

There is a monument to his memory in Hertingfordbury Church, Hertfordshire and his collection of Mughal paintings are at the Bodleian Library in Oxford (they were donated in 1859 by a Bengal civil servant, Mr JB Elliott).

His son, The Revd Canon Professor Sir Frederick Arthur Gore Ouseley (12 August 1825 — 6 April 1889) was an English composer, organist, and musicologist.