John Davis Long was an American lawyer, politician, and writer from Massachusetts. He was the 32nd governor of Massachusetts, serving from 1880 to 1883. He later served as the Secretary of the Navy from 1897 to 1902, a period that included the primarily naval Spanish–American War.

The governor of the Commonwealth of Massachusetts is the chief executive officer of the government of Massachusetts. The governor is the head of the state cabinet and the commander-in-chief of the commonwealth's military forces.