The Massachusetts Senate is the upper house of the Massachusetts General Court, the bicameral state legislature of the Commonwealth of Massachusetts. The Senate comprises 40 elected members from 40 single-member senatorial districts in the state. All but one of the districts are named for the counties in which they are located (the "Cape and Islands" district covers Dukes, Nantucket, and parts of Barnstable counties). Senators serve two-year terms, without term limits. The Senate convenes in the Massachusetts State House in Boston, the state capital.
Qualifications
The following are the qualifications to be elected to the Massachusetts Senate:
Be 18 years of age

Be a registered voter in Massachusetts
Be an inhabitant of Massachusetts for five years
Be a resident of the district when elected

Receive at least 300 signatures on nomination papers
Recent party control
Democrats hold a supermajority in the Senate.
Current leadership
Current members and districts
Massachusetts Senate districts are named for the counties that contain a portion of the district ordered by percentage of the district's population that is within that county. If multiple districts would have the same name under this scheme, they are also given an ordinal number. The one exception is "Cape and Islands" which if the naming scheme were followed would be "Barnstable, Dukes, and Nantucket".

Berkshire, Hampden, Franklin, and Hampshire
Bristol and Norfolk
First Bristol and Plymouth

Second Bristol and Plymouth
Third Bristol and Plymouth
Cape and Islands
First Essex
Second Essex
Third Essex
First Essex and Middlesex
Second Essex and Middlesex
Hampden
Hampden and Hampshire
Hampden, Hampshire, and Worcester
Hampshire, Franklin, and Worcester
First Middlesex
Second Middlesex
Third Middlesex
Fourth Middlesex
Fifth Middlesex
Middlesex and Norfolk
Middlesex and Suffolk
Middlesex and Worcester
Norfolk and Middlesex
Norfolk and Plymouth
Norfolk, Plymouth, and Bristol
Norfolk and Suffolk
Norfolk, Worcester, and Middlesex
Plymouth and Barnstable
First Plymouth and Norfolk
Second Plymouth and Norfolk
First Suffolk
Second Suffolk
Third Suffolk
Suffolk and Middlesex
First Worcester
Second Worcester
Worcester and Hampden
Worcester and Hampshire
Worcester and Middlesex