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 his wife, Heba Attena of Dornum.

[citation needed] She was probably named after her grandmother Theda of Reide, the first wife of Focko Ukena.

Between 1457 and 1465, they had six children: Heba, Gela, Enno I, Edzard I the Great, Ucko and Almuth.

[citation needed] After Ulrich's death in 1466 she took over the official business of the house Cirksena.