Sisinnios Triphyllios (, died 26 July 811) was one of the senior dignitaries of the Byzantine Empire during the reign of Byzantine empress Irene of Athens (797–802) and Nikephoros I (802–811). Sisinnios first appears in Irene's unique triumphal procession on Easter Monday, 1 April 799, through the imperial capital, Constantinople. At the time, he held the post of strategos (military governor) of Thrace, the theme closest to Constantinople, and holder of the supreme dignity of patrikios. He was one of the four patrikioi (along with Bardanes Tourkos, Constantine Boilas, and Sisinnios' brother Niketas) leading the four white horses which drew the imperial carriage, a role which marked these men out as the most prominent of Irene's supporters among the high dignitaries of the state.