Sterling Memorial Library (SML) is the main library building of the Yale University Library system in New Haven, Connecticut, United States. Opened in 1931, the library was designed by James Gamble Rogers as the centerpiece of Yale's Gothic Revival campus. The library's tower has sixteen levels of bookstacks containing over 4 million volumes. Several special collections—including the university's Manuscripts & Archives—are also housed in the building. It connects via tunnel to the underground Bass Library, which holds an additional 150,000 volumes.

The library is named for John W. Sterling, a lawyer representing Standard Oil, whose huge bequest to Yale required that an "enduring, useful and architecturally beautiful edifice" be built. Sterling Library is elaborately ornamented, featuring extensive sculpture and painting as well as hundreds of panes of stained glass created by G. Owen Bonawit. In addition to the book tower, Rogers' design featured five large reading rooms and two courtyards, one of which is now a music library.

While the library's nave and main reading rooms can be visited on guided tours, its collections are restricted to cardholders.

For the ninety years prior to the construction of Sterling Memorial Library, Yale's library collections had been held in the College Library, a chapel-like Gothic Revival building on Yale's Old Campus now known as Dwight Hall. Built to house a collection of 40,000 books in the 1840s, and later expanded to Linsly Hall and Chittenden Hall, the old library could not hold Yale's swelling book collection, which had grown to over one million volumes.

In 1918, Yale received a $17-million bequest from John W. Sterling, founder of the New York law firm Shearman & Sterling, providing that Yale construct "at least one enduring, useful and architecturally beautiful edifice." The largest bequest in the history of any American university, it initiated a major period of construction on Yale's campus. Because of the library collection's growth, the university decided to make the centerpiece of Sterling's gift a new library with a capacity for 3.5 million volumes.

The building's original architect, Bertram Goodhue, intended the library to resemble his State Capitol Building in Lincoln, Nebraska, with the library's books in a prominent tower. When Goodhue died in 1924, the project passed to James Gamble Rogers, the university's consulting architect. Rogers' work on a "General Plan" for the Yale campus allowed him to incorporate the main library project into his neo-Gothic scheme for Yale's expansion.

Roger's campus plan called for the library to sit on a new main courtyard, now called Cross Campus. Originally, he planned to balance the courtyard with a 5,000-seat chapel facing opposite the library. With the end of compulsory undergraduate chapel services in 1926 and the lack of a financier, the chapel was never built. Expanding on Goodhue's tower concept, Rogers proposed the library take the form of a cathedral, which, in his own words, would be "as near to modern Gothic as we dared to make it." He modeled the library's entrance hall to resemble a vaulted nave and commissioned extensive stained glass and stone ornament to decorate the building's exterior and interior.

The library's 122,500-square-foot (11,380 m²) footprint would take up more than half a city block. Twenty buildings were cleared for its construction, many of them private homes. Although excavation began in the fall of 1927, the construction site was not fully secured until July 1928, when the final holdout homeowner agreed to sell.