Yes, BISHOP is a Scrabble word!

Letter values in Scrabble US: B 3, I 1, S 1, H 4, O 1, P 3.

Is it a valid word?

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

a senior member of the Christian clergy having spiritual and administrative authority; appointed in Christian churches to oversee priests or ministers; considered in some churches to be successors of the twelve Apostles of Christ
port wine mulled with oranges and cloves
(chess) a piece that can be moved diagonally over unoccupied squares of the same color