Yes, FOREIGN is a Scrabble word!

Letter values in Scrabble US: F 4, O 1, R 1, E 1, I 1, G 2, N 1.

Is it a valid word?

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

of concern to or concerning the affairs of other nations (other than your own)
relating to or originating in or characteristic of another place or part of the world
not contained in or deriving from the essential nature of something
not belonging to that in which it is contained; introduced from an outside source