[1] Clinton was first settled in 1654 as a part of Lancaster after the land was deeded by Sachem Sholan of the Nashaway in 1643.

[4] Clinton became an industrialized mill town, using the Nashua River as a source for water power.

A noteworthy feature of the Boston metropolitan public water service was begun in 1896 in the Wachusett lake reservoir at Clinton.

The basin excavated there by ten years of labor, lying 385 ft. above high-tide level of Boston Harbor, had a capacity of 63,068,000,000 gallons of water and was the largest municipal reservoir in the world in 1911, yet was only part of a system planned for the service of the greater metropolitan area.

[5] Part of the Central Massachusetts Railroad line abandoned in 1958 includes a tunnel near Clamshell Road.

Clinton is bordered by Lancaster to the north, Bolton to the northeast, Berlin to the east, Boylston to the south, and Sterling to the west.

Ethnic heritages include Irish, Brazilian, Scottish, German, Québécois, Acadian, Swedish, Italian, Dominican, Puerto Rican, Mexican, Greek, and Polish.

Many emigrants from the Louisburgh area of County Mayo settled in the small town in the early 1900s, giving Clinton a large Irish population till this day.