He was grandson of Duncan Davidson (1733–1799), and succeeded to his father's Scottish estates, including Tulloch Castle.
In 1827 on his father's death, he inherited Tulloch Castle, Inchicore near Dublin, stocks and shares in various canals and the Mount Gay sugar plantation in Grenada.
In 1843 he was elected a Fellow of the Royal Society of Edinburgh, his proposer being Sir George Steuart Mackenzie.
He married five times: firstly in 1825 to Elizabeth Diana Macdonald (d.1839); secondly in 1841 to Eleanora Fergusson (d.1845); thirdly in 1846 to Arabella Ross (d.1847); fourth in 1849 to Mary Mackenzie (d.1867, his longest surviving wife); lastly in 1877 to Sarah Justine Taylor (who outlived him).
[2] He was succeeded in ownership of Tulloch Castle by his eldest son Duncan Henry Caithness Reay Davidson (1836–1889).