Kyriaki was a Christian martyr living in Nicomedia during the late third century. Born to devout parents, Dorotheus and Eusebia, she was named for the day of her birth, which was a Sunday. Having dedicated her life to Jesus Christ, she refused various marriage proposals, eventually leading a local magistrate to report her family to the emperor Diocletian. After enduring severe torture and multiple attempts to force her to renounce her faith, she was executed by the sword at the age of 21.