John Capstack (c. 1570 – January 1634) was the 13th great-grandfather of Cometan, classified as one of Cometan’s distant paternal ancestors in the McKerney family line. Born in Dent, Yorkshire, John is known to have married Agnes Capstick and to have fathered at least one son named Miles. It is also recorded that John died at the age of sixty-four in Dent, Yorkshire.
In Cometanic ancestry, John is categorised as part of the 15th generation retrograde, classifying him as a distant ancestor of Cometan.