Seo was a male Starfleet security officer in the 24th century.
By 2375, Ensign Seo served under Security Chief Padraig Daniels aboard the USS Enterprise-E. He, Jeloq and Cruzen took Gul Madred and Glinn Driana into custody after they were rescued. (TNG short story: "Four Lights")
Seo was a frontline veteran of the Dominion War. When the Enterprise was at Tezwa in 2379 to assist in the aid and rebuilding process, he had been one of the first personnel to serve on the surface; he later described in a haunted monotone with nauseatingly vivid details of a guerilla ambush in Anara-Zel that killed four security officers from the USS Republic to Fiona McEwan. (TNG novel: A Time to Heal)