Eusebius Mandyczewski (Ukrainian: Євсевій Мандичевський, romanized: Yevsevii Mandychevskyi, Romanian: Eusebie Mandicevschi; 18 August 1857, in Molodiia – 13 August 1929, in Vienna) was a Romanian musicologist, composer, conductor, and teacher.

Eusebius Mandyczewski was born in the village of Bahrynivka (Ukrainian: Багринівка; Romanian: Bahrinești)[4] (then Austria-Hungary; now Ukraine, Hlyboka Raion) on 18 August 1857.

A gifted philologist as well as musician, he was widely respected both for his scholarship and for his generosity to inquiring scholars; Grove was indebted to him for his help in the writing of his book on Beethoven's symphonies.

Mandyczewski composed music to the words of poets such as Taras Shevchenko, Yuriy Fedkovych, Vasile Alecsandri, Mihai Eminescu, and Heinrich Heine.

He arranged compositions based on many Ukrainian, Romanian, German, and Hungarian folk songs.

Nonetheless, he continued to engage in the Romanian cultural and musical life, working with local artists and often visiting the country.