Transitus Fluvii ("passing through the river" in Latin) or Passage Du Fleuve (in French) is an occult alphabet consisting of 22 characters described by Heinrich Cornelius Agrippa in his Third Book of Occult Philosophy (Cologne, 1533, but written around 1510).

The name may refer to the crossing of the Euphrates by the Jews on their return from the Babylonian captivity to rebuild the Temple in Jerusalem.

[2] This alphabet can also be found in Abraham de Balmis Peculium Abrae.

Grammatica hebraea una cum latino, Venetiis, 1523, sig.

as well as in Geoffroy Tory, Champ Fleury, Paris 1529, f. 76v ubi tamen: "Lettres Chaldaiques", and Giovanni Agostino Panteo's (Pantheus) Voarchadumia contra alchimiam, Venice, 1530, pp. 545–46.