Syncretism /ˈsɪŋkrətɪzəm/ is the combining of different (often contradictory) beliefs, often while melding practices of various schools of thought. Syncretism may involve the merger and analogising of several originally discrete traditions, especially in the theology and mythology of religion, thus asserting an underlying unity and allowing for an inclusive approach to other faiths.

Syncretism also occurs commonly in expressions of arts and culture (known as eclecticism) as well as politics (syncretic politics).

The Oxford English Dictionary first attests the word syncretism in English in 1618. It derives from modern Latin syncretismus, drawing on Greek συγκρητισμός (synkretismos), meaning "Cretan federation."

The Greek word occurs in Plutarch's (1st century AD) essay on "Fraternal Love" in his Moralia (2.490b). He cites the example of the Cretans, who compromised and reconciled their differences and came together in alliance when faced with external dangers. "And that is their so-called Syncretism."