Niobe, in Greek mythology, queen of Thebes, wife of Amphion and daughter of Tantalus. The mother of six sons and six daughters, she boasted of her fruitfulness, saying that Leto had only two children. Apollo and Artemis, angry at this insult to their mother, killed all Niobe's children. Crying inconsolably, she fled to Mt. Sipylus. There Zeus turned her into a stone image that wept perpetually.