Tiriliyan (ingiriis: Trillion) waa tiro ka mid ah xisaabta oo ka sameeysan toban-iyo-sadex god. Tiroda tiriliyan waxaa ka hooseeya ama ka yar bilyan iyo milyan. Sida eey isku raaceen khubarada xisaabta ee dunida, tirada waxaa ugu badan Tiriliyan oo ka sameeysan toban -iyo- sadex god (hal tiriliyan = 1'000'000'000'000)