The Green Mountain Boys are a militia organization first established in the late 1760s in the territory between the British provinces of New York and New Hampshire, known as the New Hampshire Grants (which later become the state of Vermont).

Headed by Ethan Allen and members of his extended family, they are instrumental in resisting New York's attempts to control the territory, over which it has won de jure control in a territorial dispute with New Hampshire.

Some companies serve in the American Revolutionary War, including notably when the Green Mountain Boys led by Ethan Allen capture Fort Ticonderoga on Lake Champlain on May 10, 1775; and invade Canada later in 1775.

In early June 1775, Ethan Allen and his then subordinate, Seth Warner, induce the Continental Congress at Philadelphia to create a Continental Army ranger regiment from the then New Hampshire Grants.

Having no treasury, the Congress directs that New York's revolutionary Congress pay for the newly authorized regiment.

In July 1775, Allen's militia is granted support from the New York revolutionary Congress.

The Green Mountain Boys disband more than a year before Vermont declares its independence in 1777 from Great Britain "as a separate, free and independent jurisdiction or state".

The Vermont Republic operates for fourteen years, before being admitted in 1791 to the United States as the fourteenth state.

The remnants of the Green Mountain Boys militia are largely reconstituted as the Green Mountain Continental Rangers.

Command of the newly formed regiment passes from Allen to Seth Warner.

Allen joins the staff of the Northern Army of New York's Major General Philip Schuyler and is given the rank of lieutenant colonel.

Under Warner the regiment fights at the battles of Hubbardton and Bennington in 1777.

The regiment is disbanded in 1779