Sir John Welch (August 1622 – 1681) was the 10th great-grandfather of Cometan, classified as one of Cometan’s distant paternal ancestors in the Stringfellow family line. Born in Great Wymondley, Hertfordshire, Sir John was the son of Sir Thomas Welch and the husband of Frances Webb (1630 – ????). Sir John is recorded to have had a son named after him who was born in 1655. Sir John is understood to have died at the age of fifty-nine.
In Cometanic ancestry, Sir John is categorised as part of the 12th generation retrograde, classifying him as a distant ancestor of Cometan.