Reinis is a Latvian masculine given name and surname and may refer to:
As a given name: Reinis Kaudzīte (1839–1920), Latvian schoolteacher and writer Reinis Nitišs (born 1995), Latvian rallycross driver Reinis Pozņaks (born 1977), Latvian politician Reinis Reinholds (born 1997), Latvian footballer Reinis Rozītis (born 1982), Latvian bobsledder and Olympic competitor Reinis Uzulnieks (born 1986), Latvian politician Reinis Zālītis (1943–2005), Latvian footballer Reinis Zusters (1919–1999), Latvian-born Australian artist
As a surname: Jānis Reinis (born 1960), Latvian actor