USS Horatio personnel
The following personnel served aboard the   in 2364. 

It was that year that her entire crew was killed in the destruction of the Horatio. Those responsible for the Horatios destruction described it as "an awful tragedy" and "a terrible loss of life." When the destruction was initially investigated by the , it was noted that "sensors [were] not detecting any bodies in the flotsam." ()

Named 
 Captain Walker Keel

Unnamed

First officer  
The first officer of the Horatio was suspected by Captain Keel to have been infested by a parasitic being, noting to Captain Picard in revealing the alien conspiracy, that he "hasn't been the same since we stopped off at Earth." When he ordered to sickbay, his medical officer assured the captain that his first officer's health was "perfectly normal." ()

Medical officer  
The medical officer of the Horatio was suspected by Captain Keel to have been infested by a parasitic being. He explained to Captain Picard that after he observed his first officer's strange behavior, he would later become suspicious of this medical officer, who said that his XO was "perfectly normal," stating of his medical officer, "I don't think I trust him either." ()

Unnamed individuals
Unnamed Starfleet personnel (24th century)