The Lyssarrian Prime Conclave was the lead government of the Lyssarrians.

Prior to 2153, the Lyssarrian Prime Conclave declared the creation of mimetic simbiots using Lyssarrian desert larvae illegal due to the ethical ramifications of creating living, sentient beings. This dictate was defied by the Velandran Circle, a group of Lyssarrian scientists, whose illegal research on simbiots had led them to make largely unsubstantiated claims of a way to stop the rapid aging process.

When Jonathan Archer decided to use the simbiot to save Charles Tucker III's life, T'Pol asked Archer if he was aware "that the Lyssarrian Prime Conclave has banned the creation of simbiots," to which Archer replied, "we don't answer to the Lyssarrian Prime Conclave." (ENT: "Similitude")