Chernobog (lit. "Black God") and Belobog (lit. "White God") are a pair of disputed Polabian deities. Chernobog appears in Helmold's Chronicle as a god of misfortune worshipped by the Wagri and Obodrites, while Belobog is not mentioned – he was constructed in opposition to Chernobog. Both gods also appear in later sources, but they are not considered reliable. Researchers do not agree on the status of Chernobog and Belobog: many scholars recognize the authenticity of these theonyms and explain them, for example, as gods of good and evil; on the other hand, many scholars believe that they are pseudo-deities, and Chernobog may have originally meant "bad fate", and was later associated with the Christian devil.

In Latin records, this theonym is noted as Zcerneboch and zcerneboth.

The 12th-century German monk and chronicler Helmold, who accompanied the Christianization missions to the Elbe Slavs, describes in his Chronicle of the Slavs the cult of Chernobog:

Also, the Slavs have a strange delusion. At their feasts and carousals, they pass about a bowl over which they utter words, I should not say of consecration but of execration, in the name of [two] gods — of the good one, as well as of the bad one — professing that all propitious fortune is arranged by the good god, adverse, by the bad god. Hence, also, in their language, they call the bad god Diabol, or Zcerneboch, that is, the black god.

Belobog does not appear in any reliable sources – he was created in opposition to Chernobog.

The next sources that speak of Chernobog and/or Belobog appear only in the 16th century. Around 1530, a Dominican friar from Pirna, Johan Lindner, recalls the gods in his compilation. Although he lived in or near the Lusatian region, he probably only used written sources and monastic stories, and not field research, which made many historians deem his work unreliable, including Georg Fabricius and Petrus Albinus. They believed that although his sources were numerous and varied, he used them uncritically. At the end of the 17th century, Abraham Frencel [de] also mentioned the Chernobog in his list of the Lusatian gods. This information is also considered unreliable because it came into being late, when the Lusatian paganism was probably completely extinct and about half of the gods he mentioned are of Prussian origin.

In 1538, the Pomeranian chronicler Thomas Kantzow in his Chronicle of Pomerania wrote:

I have heretofore related all manner of faithlessness and idolatry, in which they had engaged before the time of the German Empire. Earlier yet, their ways are said to have been even more pagan. They placed their kings and lords, who ruled well, above the gods and honored the said men [as gods] after their death. In addition, they worshipped the sun and the moon and, lastly, two gods whom they venerated above all other gods. One [of them] they called Bialbug, that is the white god; him they held for a good god. The other one [they called] Zernebug, that is the black god; him they held for a god who did harm. Therefore, they honored Bialbug, because he did them good and so that he might [continue to] do them good. Zernebug, on the other hand, they honored so that he should not harm them. And they appeased the said Zernebug by sacrificing people, for they believed that there was no better way of assuaging him than with human blood, which is actually true, if only they had seen it in the right light: that Zernebug seeks nothing other than the death of Man's body and soul.