Sigismund (variants: Sigmund, Siegmund) is a German proper name, meaning "protection through victory", from Old High German sigu "victory" + munt "hand, protection". Tacitus latinises it Segimundus. There appears to be an older form of the High German word "Sieg" (victory): sigis, obviously Gothic and an inferred Germanic form, and there is a younger form: sigi, which is Old Saxon or Old High German sigu (both from about 9th century). A 5th century Prince of Burgundy was known both as Sigismund and Sigimund (see Ernst Förstemann, Altdeutsche Personennamen, 1906; Henning Kaufmann, Altdeutsche Personennamen, Ergänzungsband, 1968). Its Hungarian equivalent is Zsigmond.

A Lithuanian name Žygimantas, meaning "wealth of (military) campaign", from Lithuanian žygis "campaign, march" + manta "goods, wealth",^[1] has been a substitution of the name Sigismund in the Lithuanian language, from which it was adopted by the Ruthenian language as Жыгімонт (such are the cases of Sigismund Kęstutaitis, Sigismund Korybut, Sigismund I the Old, Sigismund II Augustus). The Polish spelling is Zygmunt, and the Serbo-Croatian variant is Žigmund.

• Sigismund, a Space Marine character from the Warhammer 40,000 novel series, The Horus Heresy
• Sigismund Arbuthnot, the "mad maths master" in the Molesworth books

• Sigismund Bell, a bell in Wawel Cathedral in Kraków

• Sigmund (given name) for people named Sigmund or Siegmund
• Segismundo, main character of Calderón de la Barca's La vida es sueño