Stilgar is a fictional character in the Dune universe created by Frank Herbert. He appears in the first three novels in the series: Dune (1965), Dune Messiah (1969) and Children of Dune (1976). His early life is explored in Brian Herbert and Kevin J. Anderson's Prelude to Dune trilogy (1999-2001), and the character is brought back as a ghola in their conclusion to the original series, Sandworms of Dune (2007).
In his youth, Stilgar and two friends, Turok and Ommun, had been cornered by thuggish Harkonnen troopers. Badly injured, Stilgar would have died if Pardot Kynes had not come and helped kill the troops. Because of this water-debt, Stilgar and Pardot Kynes became good comrades. Stilgar, Turok and Ommun promised to help Kynes achieve his dream of turning Arrakis into a paradise. When Pardot Kynes died, Stilgar was a very good friend to his son Liet Kynes, and thereby something of a paternal figure to Liet's daughter Chani (later concubine/wife of Paul "Muad'dib" Atreides).
In the novel Dune, Stilgar met Paul and his mother Lady Jessica when the Atreides fled into the desert, escaping a Harkonnen attack. Like the other Fremen, Stilgar eventually believed that Paul was their long-foretold Messiah, the Mahdi. Stilgar had two wives, one of whom was named Tharthar. He later also married Harah, a woman whom Paul had "acquired" as his servant, according to Fremen custom, after defeating her husband Jamis in a ritual battle to the death.
Subsequently, in Dune Messiah and Children of Dune, Stilgar was a staunch supporter and protector of Paul and his children, Leto II and Ghanima. In Messiah, Stilgar executed the Bene Gesserit Reverend Mother Gaius Helen Mohiam and Spacing Guild Navigator Edric (as well as former Fedaykin Korba) on orders from Paul's sister Alia, after their conspiracy to topple Paul's empire failed. In Children, Stilgar helped Ghanima and the Princess Irulan escape Alia's later tyranny.