Hailing from a tiny farming community in western La Jose, Pennsylvania, his conversion was as a teenager in Akron, Ohio. While on his way home from work at a tire company, he overheard a street preacher say: "If you don't know how to be saved... just call on God." Upon returning home, he climbed into the attic and heeded the preacher’s advice.
In 1919, five years after his conversion, and without formal theological training, Tozer accepted an offer to pastor his first church. This began 44 years of ministry, associated with the Christian and Missionary Alliance (C&MA), a Protestant Evangelical denomination; 33 of those years were served as a pastor in a number of churches. His first pastorate was in a small storefront church in Nutter Fort, West Virginia. Tozer also served as pastor for 30 years at Southside Alliance Church, in Chicago (1928 to 1959), and the final years of his life were spent as pastor of Avenue Road Church, in Toronto, Canada. In observing contemporary Christian living, he felt that the church was on a dangerous course toward compromising with "worldly" concerns.
"Born into poverty" Tozer was self-educated teaching "himself what he missed in high school and college due to his home situation." In 1950, Tozer received an honorary Doctor of Letters degree from Wheaton College. It was May 1950, when Tozer was elected editor of the Alliance Weekly magazine, now called, Alliance Life, the official publication of the C&MA. From his first editorial, dated June 3, 1950, he wrote, "It will cost something to walk slow in the parade of the ages, while excited men of time rush about confusing motion with progress. But it will pay in the long run and the true Christian is not much interested in anything short of that." In 1952, he received an LL.D. degree from Houghton College.
Among the more than 40 books that he authored, at least two are regarded as Christian classics: The Pursuit of God and The Knowledge of the Holy. His books impress on the reader the possibility and necessity for a deeper relationship with God.
Living a simple and non-materialistic lifestyle, he and his wife, Ada Cecelia Pfautz, never owned a car, preferring bus and train travel. Even after becoming a well-known Christian author, Tozer signed away much of his royalties to those who were in need.
Tozer had seven children, six boys and one girl. He was buried in Ellet Cemetery, Akron, Ohio, with a simple epitaph marking his grave: "A. W. Tozer - A Man of God." 
Prayer was of vital personal importance for Tozer. "His preaching as well as his writings were but extensions of his prayer life," comments his biographer, James L. Snyder, in the book, In Pursuit of God: The Life Of A.W. Tozer. "He had the ability to make his listeners face themselves in the light of what God was saying to them," writes Snyder.
Over the years many have been inspired by the life and sermons of Tozer. In 2011, Christian music artist Lauren Barlow of BarlowGirl published a compilation of stories told by 59 artists, writers, and leaders about how A.W. Tozer inspired them.
There are also many compilations of sermons and other writings which were edited and published by Christian Publications, Inc. and Regal Books, after Tozer's death. Although the following books were published posthumously, authorship is attributed to A. W. Tozer. (This list is by no means complete.):
The Attributes of God, Volume One with study guide by David E. Fessenden (1997) ISBN 0-87509-957-2
The Attributes of God, Volume Two with study guide by David E. Fessenden (2001) ISBN 0-87509-988-2