McGinley was educated at the University of Southern California and at the University of Utah in Salt Lake City. After receiving her diploma in 1927, she taught for a year in Ogden and then at a junior high school in New Rochelle, New York. Once she had begun to establish a reputation for herself as a writer, McGinley gave up teaching and moved to New York City, where she held various jobs. She married Charles Hayden in 1937, and the couple moved to Larchmont, New York. The suburban landscape and culture of her new home was to provide the subject matter of much of McGinley's work.
McGinley was elected to the National Academy of Arts and Letters in 1955. She was the first writer to win the Pulitzer for her light verse collection, Times Three: Selected Verse from Three Decades with Seventy New Poems (1960).
In addition to poetry, McGinley wrote essays and children's books, as well as the lyrics for the 1948 musical revue Small Wonder.