O'Malley was born in 1909 into an Irish immigrant family in Clinton, Massachusetts, where his father worked in a cotton mill.
[2] After graduating from high school at the top of his class, he spent two years working at a drug store to save money to attend university.
[7] O'Malley enjoyed and excelled at teaching freshman composition, encouraging his students to "write something fresh about a tree, the feeling of alienation, their first kiss".
It introduced students to recent and contemporary Catholic authors working in a various disciplines and became "by far the most popular course in the humanities ever offered at the university".
[3] His thinking and teaching were influenced by contemporary European Catholic lay intellectuals, including Waldemar Gurian, Jacques Maritain, and Étienne Gilson.