He married in 1790 and, the following year, his first son (also called John Farey) was born. John Farey Jnr (1791-1851) went on to become a civil engineer and also has an entry in the Dictionary of National Biography immediately following that of his father.
Siya ang may-asawa at sa 1790, ang mga sumusunod na mga taon, ang kanyang unang anak na lalaki (tinatawag din na John Farey) ay ipinanganak. John Farey Jnr (1791-1851) nagpunta sa na maging isang civil engineer at din ay isang entry sa Diksyunaryo ng National buhay agad-agad na sumusunod na ng kanyang ama.