Theda Ukena (1432 in Oldersum – 16 November 1494 in Greetsiel) was from 1466 to about 1480 regent of the County of East Frisia.Theda was the granddaughter and heiress of the chief Focko Ukena (died 1436) and was born in 1432 in Oldersum as the daughter of Uko Fockena and Heba Attena of Dornum. She was probably named after her grandmother Theda of Reide, the first wife of Focko Ukena.