Major-General Sir Thomas Dennehy, CIE (1829–1915), born in County Cork, Ireland and educated in Paris, was an administrator in British India.
Dennehy served in the suppression of Sonthal rebellion in 1855–56 and during the Indian Rebellion of 1857. He was Political Agent in Dholpur in 1879–85. He was extra Groom in Waiting to Queen Victoria in 1888 and to Edward VII in 1901. He was in charge of the queen's Indian servants and received a Grace and Favour apartment at Hampton Court Palace. He resigned in 1900. Unusually, his daughter Elsie was given joint permission to occupy the apartment with her father, even though she had married a Mr. Hallaham in 1894.
By 1892, Dennehy had a residence in Ireland, at Brooklodge, Fermoy, Co. Cork.
One of Dennehy's servants in India, Mohammed Buhsh, was one of the two Indian servants sent, by Sir John Tyler, Governor of the North-West Provinces, to Queen Victoria in 1887; the other was Abdul Karim, known as The Munshi (teacher), who replaced the more famous John Brown in the queen's affections.