Yes, WESTERNS is a Scrabble word!

Letter values in Scrabble US: W 4, E 1, S 1, T 1, E 1, R 1, N 1, S 1.

Is it a valid word?

WESTERNS is a valid word in the official Scrabble dictionary (US), the UK Scrabble Dictionary and Words with Friends (ENABLE).

a film about life in the western United States during the period of exploration and development
a sandwich made from a western omelet

Also: horse opera, western sandwich.