Mycenae - Mask of Agamemnon was discovered here in 1876 by Heinrich Schliemann. The artifact is a funeral mask hewn in gold (wiki)
See en.wikipedia.org

Venetian masks are a centuries-old tradition of Venice. The masks are typically worn during the Carnevale (Carnival of Venice), but have been used on many other occasions in the past, usually as a device for hiding the wearer's identity and social status. (wiki)
See en.wikipedia.org

especially within the age-passage rites that dances and masks play an important role (AB ev)

Jade mask found inside Pyramid of the Sun
See www.pasthorizonspr.com

Among the Haida, masks were used mostly by members of the secret societies.
See www.civilization.ca

Itsukushima's Shinto priest wears golden mask topped with dragon during the Shinto ritual dance.

Hahoe Byeolsingut Tallori (Masked-dance Drama of Hahoe Village, Important Intangible Cultural Property No. 69)- Nomination File

Eine Maske mit menschlichen Zügen wurde als Teil eines Totempfahls interpretiert, wie er auch in Nevali Cori gefunden wurde. (wiki de)

The Dogon have complex religious rituals that involve animal masks.

The faces of the mummies received artificial treatment, like mud or clay masks. (Chinchorro Culture Nomination Text, p. 111-113)

Burial mask of Tutankhamun's mummy