Boston, Massachusetts is the headquarters for the DFS site giant DraftKings so you can play fantasy sports. It is legal in the state. While DraftKings rules the landscape, you can still find many other DFS sites in Massachusetts such as FantasyDraft, Monkey Knife Fight and FanDuel app.
While Daily Fantasy Sports have been made legal in the state; since Massachusetts passed its 2016 DFS Law, there were provisions with this that came in the form of a sunset style provision in July of 2019. However, an amendment was submitted to quickly remove the provision and continue daily fantasy sports in the state and city of Boston permanently. This means that residents of Massachusetts are able to play on sites like FanDuel and DraftKings DFS legally.