Lady Elizabeth Leigh (née de Sandback; c. 1318 – ????) was an English noblewoman and the 25th great-grandmother of Cometan, classified as one of Cometan’s medieval paternal ancestors in the Taylor family line.

Lady Elizabeth is known to have been born in Sandbach, Congleton, Cheshire and is thought to have died somewhere in Cheshire, although a date of death remains unknown. She was the wife of Sir John Leigh and was the mother of Maud Matilda de Radcliffe who connects to the Cometanic ancestry. Lady Elizabeth was also the daughter of Richard de Sandback, although the identity of her mother remains unknown. 

In Cometanic ancestry, Lady Elizabeth is categorised as part of the 27th generation retrograde, and because she was born before 1453, she is classified as a medieval ancestor of Cometan, a title that is rarely bestowed.