Isidore (, sometimes spelled Isidor, Isadore, or Isador) is a male given name of Greek origin, derived from Ἰσίδωρος, Isídōros (a compound of Ἶσις, Ísis, and δῶρον, dōron: "gift of [the goddess] Isis").
Similar "gift" names include the Greek "Theodore" ("gift of God") and "Apollodorus" ("gift of Apollo") , the Persian "Mithradates" ("gift of Mithras") and Datis ("gift"), and the Hebrew "Matanya" ("gift of YHWH"). The Indo-European "gift" names are ultimately derived from the *PIE root *deh₃-, "to give".
The fact of several prominent Christian Saints (see below) being named "Isidore" ensured the survival of the name, beyond the extinction of the worship of Isis, and up to the present.
Isidora is the equivalent female given name.
People with the name Isidore include:
- Isidore of Seville (c. 560–636), Scholar, last of the Fathers of the Church, Archbishop of Seville, Catholic saint and the most notable individual named Isidore.
- Isidore of Chios (d. 251), Roman Christian martyred on the island of Chios
- Isidore I of Constantinople, Ecumenical Patriarch in 1347–1350
- Isidore II of Constantinople, Ecumenical Patriarch in 1456–1462
- Isidore of Kiev (1385–1463), Greek religious leader and theologian
- Isidore the Laborer (c. 1070–1130), Spanish religious leader
- Isidore of Pelusium (died c. 449), Egyptian theologian
- Chief Isadore (fl. 1860s), leader of the Ktunaxa/Kootenay people in the Tobacco Plains War
- Isidore (inventor) (fl. 15th century), Russian religious leader and distiller
- Isidoro, nom de guerre of Felipe González (born 1942), socialist leader in Franco-era Spain
- Isador Coriat (1875–1943), American psychiatrist and neurologist
- Isadora Duncan dancer
- Izzy Einstein (1880–1938), American policeman during the prohibition period
- Isadore "Friz" Freleng (1906-1995), American cartoonist
- Isador Goodman (1909–1982), South African-Australian musician and composer
- Isidore of Miletus (fl. 6th century), architect
- Isidore Newman (fl. 1903), founder of the Isidore Newman School
- Isidor Philipp (1863–1958), Hungarian-French pianist, composer and pedagogue
- Isidor Isaac Rabi (1898–1988), Galician-born American physicist and Nobel laureate
- Sir Isidore Spielmann (1854–1925) British art critic and exhibition organizer
- Isidor Straus (1845–1912), co-owner of Macy's, drowned in the sinking of RMS Titanic
- Isidor Gunsberg (1854-1930), Hungarian chess player
- Isador Samuel Turover (1892–1978), Belgian-American chess master
- Isidore (platform), is a web-based platform dedicated to the sharing of scientific knowledge in human and social sciences.
- Isadore Nabi, pseudonym used by a group of scientists including Richard Lewontin, Richard Levins, Robert MacArthur, and Leigh van Valen in the 1960s.
- San Isidro (other), Spanish for "Saint Isidore", and the name of several people and places
- Jack Isidore, a fictional character in Philip K. Dick's novel Confessions of a Crap Artist
- John R. Isidore, a fictional character in Philip K. Dick's novel Do Androids Dream of Electric Sheep?
- Isidore Saack is a fictional character in Gaston Leroux's Phantom of the Opera
- "Isidore" is a song by Incubus (band) on If Not Now, When? (album).