Sir Knight John de Arderne of Aldford (c.1266 – June 1, 1308) was the 27th great-grandfather of Cometan, classified as one of Cometan’s medieval paternal ancestors in the Taylor family line.  

Sir John is known to have been born in Aldford, Cheshire and is thought to have died in Alvanley, Runcorn, Cheshire. He was the husband of Margery verch Gruffydd and was the father of Maud de Arderne who connects him to the Cometanic ancestry. Sir John was also the son of Sir Peter de Arderne and Margery de Elleford. 

In Cometanic ancestry, Sir John is categorised as part of the 29th generation retrograde, and because he was born before 1453, he is classified as a medieval ancestor of Cometan, a title that is rarely bestowed.