The USS Horatio Nelson was a Starfleet frigate during the late-24th century. It was a part of a fleet that won the decisive Battle of Sector 21505 in the final days of the Federation-Cardassian border conflict. Its crew discovered that the automated Cardassian dreadnaught running kamikaze maneuvers at the Federation fleet was controlled by a single Galor-class warship.
Following the Klingon invasion of the Cardassian Union, the Horatio Nelson was again assigned to Cardassian space
The Horatio Nelson’s commander, Ronnie Kozar was recommended by Admiral Edward Jellico for the position of commanding officer of the USS Lambda Paz in 2374. Fleet Admiral Alynna Nechayev chose ex-Maquis Limis Vircona instead and assigned Kozar as first officer. Tactical officer Mandel Morrison and Communications officer Shinar sh'Aqba were other Horatio Nelson crewmembers assigned to the Lambda Paz (Star Trek: Lambda Paz: "Revenge a Dish Best Served Cold").