Devon Riyannis, née Yarvo, was a male Trill active as a non-commissioned officer in the Federation Starfleet in the mid-24th century. Devon spent thirty years in Starfleet with a transporter officer rating, reaching the grade of master chief petty officer before hitting mandatory retirement. During part of his career he served with then-Ensign Jadzia Dax, and remarked that she was smart to pay attention to her noncoms. He was married and divorced twice and did not have custody of his children. Devon died of a stroke two years after retirement.