Russian Brazilians are Brazilian citizens of full or partial Russian ethnic background or Russian-born people residing in Brazil. The term can also refer to someone with a Brazilian mother and Russian father, or vice versa.

The Russians are an East Slavic ethnic group indigenous to Eastern Europe, who share a common Russian ancestry, culture, and history. Russian, the most spoken Slavic language, is the shared mother tongue of the Russians; Orthodox Christianity has been their majority religion since the formation of a Russian identity in the Middle Ages. They are the largest Slavic nation and the largest European nation.