James FitzHenry (also Fitzhenry, Fitz-Henry), curate of the Roman Catholoc church, was the son of Michael FitzHenry and his wife Mary, born Meyler. By 1874 he resided in Port Elizabeth, but in later years his work took him to various towns in the Cape Colony. He was active in various local scientific societies and had a particular interest in geology. When the short-lived South African Geological Association was formed in Grahamstown in June 1888 he was elected as a member of its first committee. Members of the association lived all over the country, with the result that it met infrequently. At the next meeting, again in Grahamstown, on 17 January 1889, FitzHenry read a papper on the coal measures of South Africa. By the time of the society's annual meeting in July 1890, held in Port Elizabeth, he had translated into English a paper by the German geologist Adolf Schenck*, on the geological development of South Africa. Long extracts from his translation were read to the meeting on his behalf.
By this time FitzHenry had moved to Grahamstown, where he served on the committee of the Albany Museum during 1890 and 1891. When the Albany Natural History Society was founded in November 1890 (an earlier society with this name had existed in Grahamstown in 1867-1875) he was elected as joint vice-president, and re-elected to that position in March 1892. In May 1892 he was present at the formation of the Eastern Province Literary and Scientific Society in Grahamstown and was elected on its first committee the next month. In July he delivered the first monthly lecture before the society, being a description of the Zimbabwe ruins and speculations on its origins, based on the work of Theodore Bent*. FitzHenry and some others advocated the amalgamation of the various local scientific societies, with the result that the Albany Natural History Society amalgamated with, and became the Natural History Section of, the Eastern Province Literary and Scientific Society in October 1892. FitzHenry became a member of its sub-committee for natural history. He remained an office bearer until he left Grahamstown in 1894.
In 1896 he and several others were elected honorary members of the Geological Society of South Africa, founded the previous year. In 1898 he was living in Port Elizabeth again, but in 1903 resided in Naauwpoort (now Noupoort, a station north of Middelburg) and had become an early member of the South African Association for the Advancement of Science. In the membership list for 1906 he is listed as "Chaplain to Forces" in Middelburg. His "Notes on the petroleum indications around Harrismith" were published in the association's Report for 1907 (pp. 76-77). He was buried in Grahamstown.