Charles Aubrey Eaton was born in Pugwash, Nova Scotia, Canada in 1868. His early life was marred by poverty and ill health that interfered with his education, but as the result of a religious conversion experienced under the influence of a clergyman he met as a young man, he was inspired to recover lost ground, and he eventually graduated from Acadia University, a Baptist institution in Wolfville, Nova Scotia, where he studied divinity. He became renowned in the cities where he preached for lively, exhortative, and often humorous oratory that both reawakened religious lagards and attracted new converts to the Evangelical movement.

Despite his personal success, Charles Eaton was a sensitive observer whose own humble origins made him keenly aware, as his experience broadened, of the extreme poverty and social dislocation caused in the working classes by the rapid industrialization of America in the late nineteenth century and early twentieth century. During the Progressive era, he became deeply interested in movements, including those within the Protestant churches, for social amelioration, and personally championed policies in his own churches that transformed them into more effective servants of the needs of the less fortunate. As an example of his intense commitment, in 1904 he was arrested on the streets of Cleveland, Ohio for persistently ignoring by-laws prohibiting street preaching, a practice he felt obliged to in order that his message would reach those who needed it. A talent for persuading and motivating groups of people, large and small, was the foundation for a wide appeal, and would eventually bring him to the attention of men who would lead him out of the narrowing church sphere into journalism, business, and national political life.

As a result of his religious work in Cleveland, he was soon after arriving there welcomed into the society and Christian fellowship of John D. Rockefeller, who as a summer resident of Cleveland attended Euclid Avenue Baptist Church, where Eaton preached. Rockefeller became a life long friend, and this connection influenced Eaton's future path in many ways.

In 1924, Eaton was elected as a Republican to the Sixty-ninth United States Congress and to the thirteen succeeding Congresses, serving until 1952. He rose to become chairman of the Committee on Foreign Affairs (Eightieth Congress), and served on the Select Committee on Foreign Aid (Eightieth Congress). For several years, he served in Congress alongside his nephew William Robb Eaton, a Representative from Colorado.

Twenty days after his retirement from Congress, Eaton died in Washington, D.C. Eaton was interred in Hillside Cemetery located in Scotch Plains, New Jersey.