A Duma (Ukrainian: дума, plural dumy) is an oral epic poem which originated in Ukraine during the Cossack Era in the sixteenth century, possibly based on earlier Kyivan epic forms. Historically, dumy were performed by itinerant Cossack bards called kobzari, who accompanied themselves on a kobza or a bandura, who were often (blind) itinerant musicians who retained the kobzar appellation and accompanied their singing by playing a bandura (rarely a kobza) or a relya/lira (a Ukrainian variety of hurdy-gurdy). Dumas are sung in recitative, in the so-called "duma mode", a variety of the Dorian mode with a raised fourth degree.

Dumy were vocal works built around historical events, many dealing with military action in some forms. Embedded in these historical events were religious and moralistic elements. There are themes of the struggle of the Cossacks against enemies of different faiths or events occurring on religious feast-days. Although the narratives of the dumy mainly revolve around war, the dumy themselves do not promote courage in battle. The dumy rather impart a moral message on how one should conduct oneself properly in the relationships with family, community, and church. Modern scholarship has stressed that the prominence of death, defeat and lament in the dumy does not set them apart from other epic traditions: similar patterns of heroic death and tragic denouement are also found in the Song of Roland, the Nibelungenlied, Beowulf and other European heroic narratives. However, the kobzari did not play only religious songs and dumy. They also played "satirical songs (sometimes openly scabrous); dance melodies; either with or without words; lyric songs; and historical songs". In the 1920s and 1930s the first large-scale scholarly corpus of Ukrainian dumy was prepared by folklorist Kateryna Hrushevska for the All-Ukrainian Academy of Sciences. Her two-volume edition Ukrainski narodni dumy (1927; 1931) assembled, critically compared and annotated many recorded variants of epic songs and is regarded in later scholarship as a foundational reference work for the study of the duma tradition.^{[full citation needed]}

First mention of the term "Duma" in the meaning of epic song comes from a Polish translation of the Bible published in Kraków in 1561. The word duma originates from Polish rather than from Ukrainian (or Ruthenian). The word duma was already used in Old Polish literature (Old Polish literature spanned from the medieval period through the Baroque era). Polish Dumas typically told of the deeds of a historical hero or an otherwise unknown person who had achieved something noteworthy. Its action was usually set in an atmospheric landscape and included reflections on the past. The style of the duma was simple, often drawing on elements of everyday speech. Later, Polish dumy were also written with elements of the supernatural—centered on meditations over knights’ graves, ruins, or nocturnal settings—as well as romantic dumy recounting the amorous adventures of knights. Poles used the word duma for their own ballades as well as foreign ballades (including Ukrainian ones), from very early on, Mikołaj Rej called Ukrainian epics dumy. Some popular Polish dumy include "Duma o Żółkiewskim", "Duma o Chodkiewiczu", and "Duma Kamieniecka."

While the name ”duma” for Ukrainian epic songs is a Polonism (a word borrowed from Polish), the songs themselves do not derive from Polish literary or musical traditions. Ukrainian dumy constitute an indigenous oral-epic form rooted in the historical and social experience of the Cossack Hetmanate and transmitted by itinerant bards known as kobzari and bandurysty.

In the early 19th century, the Russian poet Kondraty Ryleyev applied the term duma to historical or heroic songs in East Slavic culture, following his translation of Niemcewicz's “Duma o Michale Glińskim” (“Duma about Michał Gliński”). This adaptation popularized the word across the Slavic literary world, where it came to denote epic or patriotic songs associated with national history and heroism.

The relationship between the military and the religion with dumy originated in the times of the Cossack rebellion of 1648. Ukraine fell under the control of the Catholic Polish-Lithuanian Commonwealth, that imposed discriminatory measures on the Eastern Orthodox Church. This rebellion was followed by “partition and eventual subjugation of the Ukrainian lands and the Ukrainian church. The Cossacks rebelled against the religious oppression and their lands were eventually lost to the oppressor. This causes a great dilemma in the church because the Cossacks were defenders of the faith, and since they lost, and the faith is infallible, the Cossacks themselves must have done something sinful. This is why a duma has a great religious undertone and is a song that tells of death and defeat, not of victory. Pavlo Zhytetsky suggested that the style of duma's evolved as a unique combination of folk and educated cultures.

The Encyclopedia of Ukraine describes dumy as lyrico-epic works of folk origin that arose in the sixteenth and seventeenth centuries out of the military and social life of the Zaporozhian Cossacks and frontier communities, only later acquiring the name duma. Filaret Kolessa’s classic study of the genre’s genesis argues that their style developed through the interaction of older historical songs, church chant and the syllabic verse of early modern school drama and religious poetry.

Some scholars push the roots of the genre further back. Drawing on comparative metrics and motifs, Kolessa and later authors have pointed to similarities between dumy and earlier East Slavic chant and lament traditions, including the medieval Slovo o polku Ihorevi, and have suggested lines of continuity between Kyivan-period epic forms and the Cossack-era dumy. In a different line of argument, Natalie Kononenko notes that many Western researchers understand dumy, together with South and East Slavic heroic songs, as regional survivals of a broader, hypothetical Proto-Slavic epic tradition rather than isolated creations of the seventeenth century.