No. Sports betting was not legal in Massachusetts as of spring 2020. However, after approval by the Governor and state lawmakers, there's a chance a bill is pushed through by the end of the year. While specifics have to be sorted out, Massachusetts is set to be one of the next states to legalize sports betting.
The question is if the Coronavirus pandemic will delay the bill from passing through the House Ways and Means Committee even though the joint committee gave a recommendation that it ought to pass. The deadline for the bill to pass is July 2020 and if it doesn't, Massachusetts may have to wait until 2021 to legalize sports betting.
As for the specifics, the bill would authorize sports betting at three casinos, one slot parlor, horse racing tracks and up to five online-only operators.
Like most states, Daily Fantasy Sports and horse racing betting are both legal in the state. Fantasy sports were legalized in 2016 with a couple different rules than most states. Most notably, the minimum age of participation for DFS is 21 years old compared to 18 almost everywhere else, while contests involving college games are not allowed. More relevant for the state is that there are no fees or taxes for fantasy contests.