John Gill entered Boston printing through Samuel Kneeland's shop and became Benjamin Edes's partner in the Boston Gazette. Their first issue appeared on April 7, 1755. From their Queen Street office they published a weekly newspaper that became an important vehicle for opposition to British imperial measures. Gill set type, operated the press and prepared the paper with contributors.

John Adams described spending an evening in September 1769 with Gill, James Otis, Samuel Adams and William Davis assembling material for the next day's issue. The printers' refusal to identify anonymous writers could bring personal consequences. In 1768 John Mein, angered by an essay in the Gazette, struck Gill with a cane after the partners refused to disclose its author. Gill sued, and Mein was fined and ordered to pay damages.

The partnership's final Boston issue appeared on April 17, 1775. Edes left the town and continued publication elsewhere, while Gill remained through the siege. British military authorities imprisoned him, and the occupation interrupted his business. After the evacuation the partners divided their printing stock and ended their connection. Gill began the Continental Journal in May 1776, once again publishing in Queen Street. He continued it for most of the rest of his life before selling the newspaper and printing materials to James D. Griffith in 1785. He died that August, after three decades producing newspapers through Boston's political crisis and the Revolution.