Brewster is represented in the Massachusetts House of Representatives as a part of the First Barnstable District, along with Dennis and a portion of Yarmouth. The town is represented in the Massachusetts Senate as a part of the Cape and Islands District, which includes all of Cape Cod, Martha's Vineyard and Nantucket except the towns of Bourne, Falmouth, Sandwich and a portion of Barnstable. The town is patrolled by the Second (Yarmouth) Barracks of Troop D of the Massachusetts State Police.