Lieutenant-General James Francis Tennant (10 January 1829 – 6 March 1915) was a noted soldier and astronomer.
He was born in Calcutta to Scottish parents.
In 1859, when he rejoined the survey, he was given the directorship of the Madras Observatory where his interest in astronomy started.He was noted for being an observer for the Royal Astronomical Society for the solar eclipse of 17 August 1868 across the Indian peninsula, and that of 11 December 1871 across Southern India, and later the transit of Venus of 1874.
It is during these observations that photographic equipment was used extensively for the first time, Tennant was a practiced expert in photography and his skill aided the observations of the eclipses, in particular that of the corona.
In 1876 he was appointed Master of the Royal Mint, a position he held until his retirement in 1882, when he returned to England.
He was elected to the council of the Royal Astronomical Society in 1885, and between 1890 and 1891 he served as president, at this time he had an interest in comets and contributed to several orbital calculations.