The Ylesian Senate was the legislative body of the Ylesian Republic, formed out of the sixty former members of the Alliance of Twelve. It was based in the Palace of Peace in Peace City.
The amount of authority it actually exercised was unknown, but it was most likely minimal. It was known that all of its members were Peace Brigaders. The entire Ylesian senate was captured along with President and Commander-in-Chief Thrackan Sal-Solo when the New Republic attacked the planet.