Modrej (; in older sources also Modreja) is a settlement on the left bank of the SoÃÂa River, just north of Most na SoÃÂi, in the Municipality of Tolmin in the Littoral region of Slovenia.
Modrej was attested in historical sources as Modrea in 1377. The name is believed to be derived from the nickname *ModrÃÂjÃÂ, formed from the anthroponym *ModrÃÂ, based on the color adjective *modrà'blue'. It is unlikely that the name is derived from the adjective *mëdrà'wise'.