Otera Tul was a Trill individual and President of Trillius Prime in the early 25th century.
In 2406, President Tul sent a communique to T'Vanik, Secretary General of the Federation Security Council, stating that the Trill government denied that any security breaches had occurred in the Caves of Mak'ala, the home of the Trill symbionts. The rumors were that the Undine, Species 8472, were using the caves to infiltrate the Alpha Quadrant from fluidic space. President Tul declined the offer of Starfleet troops to be deployed to the Caves of Mak'ala. (STO novel: The Needs of the Many)