In addition to "The Ones Who Walk Away from Omelas," she wrote a novel set on the planet Urras and its moon Anarres.  
One of this author's stories is set during the Festival of Summer in a city whose grandeur rests entirely on the privations of a feeble-minded child kept locked up in a tiny room; the child's plight occasionally leads an inhabitant of the title city to leave for the mountains.  In addition to "The Ones Who Walk Away from Omelas," she wrote a novel set on the planet Urras and its moon Anarres.  A daughter of the dragon Kalessin is the title character of another of her novels, which continues the storyline of an early trilogy focusing on the wizard Sparrowhawk in such novels as The Farthest Shore and The Tombs of Atuan.  FTP, name this author of Tehanu, The Dispossessed, and The Earthsea Trilogy.
One of this author's stories is set during the Festival of Summer in a city whose grandeur rests entirely on the privations of a feeble-minded child kept locked up in a tiny room; the child's plight occasionally leads an inhabitant of the title city to leave for the mountains.  
Ursula Kroeber Le Guin (note, in case anyone cares: Tehanu is the daughter of Kalessin, and The Dispossessed is set on Urras and Anarres; the rest should be fairly clear)