- Star Trek: The Motion Picture
- Star Trek II: The Wrath of Khan
- Star Trek III: The Search for Spock
- Star Trek IV: The Voyage Home
- Star Trek V: The Final Frontier
- Star Trek VI: The Undiscovered Country
- Star Trek Generations
Famed deaf mediator from planet Ramatis III who negotiated several treaties between the Klingon Empire and the Federation and never failed to find a diplomatic solution. A member of his planet's ruling family which lacked the gene for hearing, Riva used a "Chorus" of aides who were telepathically linked with him and acted as his interpreters. In 2365, the Enterprise-D took Riva and his Chorus to Solais V to negotiate an end to 1500 years of hostilities. During the initial meeting with the two factions on the planet, violence erupted and the Chorus was killed, leaving Riva without his normal mode of communication. With the Enterprise crew's support, Riva opted to bring the warring sides together by teaching them sign language, thus fulfilling his own philosophy of turning disadvantage into advantage. He stayed behind on Solais V, alone with the local inhabitants, to continue the long process of bringing peace to the war-torn planet.