Yes, VICEROY is a Scrabble word!

Letter values in Scrabble US: V 4, I 1, C 3, E 1, R 1, O 1, Y 4.

Is it a valid word?

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

governor of a country or province who rules as the representative of his or her king or sovereign
showy American butterfly resembling the monarch but smaller

Also: limenitis archippus.