[1] The library's original architects, Charles H. Bebb and Carl F. Gould,[1][2] called for three structures built in Collegiate Gothic style[1][2] and arranged in a roughly equilateral triangle with a bell tower in the center.

The original plans for the third wing of the library, completed in 1963, were extensively revised, as by this time the university had largely moved away from its earlier architectural style and had adopted instead modernist concrete and glass forms.

[4] The 250-foot (76 m) long, 52-foot (16 m) wide, 65-foot (20 m) high Graduate Reading Room[1][5] (illustrated below) features cast-stone ashlar wall blocks and details, and oak bookcases topped with hand-carved friezes of native plants, under a painted and stenciled timber-vaulted ceiling.

Its distinctive look, reminiscent of the great halls of Oxford and Cambridge colleges, is also said to have been inspired by Henry Suzzallo's stated belief that universities should be "cathedrals of learning."

Adorning the exterior of the early wings are terra cotta sculptures by Allen Clark of influential thinkers and artists selected by the faculty.

These include Moses, Louis Pasteur, Dante Alighieri, Shakespeare, Plato, Benjamin Franklin, Justinian I, Isaac Newton, Leonardo da Vinci, Galileo Galilei, Johann Wolfgang von Goethe, Herodotus, Adam Smith, Homer, Johann Gutenberg, Ludwig van Beethoven, Charles Darwin and Hugo Grotius.

The front façade is also decorated with stone coats of arms from universities around the world, including Toronto, Louvain, Virginia, California, Yale, Heidelberg, Bologna, Oxford, Paris, Harvard, Stanford, Michigan, Uppsala, and Salamanca.