Ieoh Ming Pei (貝聿銘) (born April 26, 1917), commonly known by his initials I. M. Pei, is a Pritzker Prize-winning Chinese-born American architect, known as the last master of high modernist architecture.

Pei was born in Canton (now called Guangzhou), China on April 26, 1917, to a prominent family. His father, a banker, was later the director of the Bank of China and the governor of the Central Bank of China. His family later moved to Shanghai, but resided in Suzhou, a city near Shanghai. The family's residence is in a renowned garden in Suzhou, now part of the World Heritage Site listed Classical Gardens of Suzhou. The house was called the Garden of the Lion Forest, and consisted of many rock sculptures carved naturally by water. Pei loved how the buildings and the nature were combined, and especially liked the way light and shadow mixed.

His first education was at St. Paul's College, Hong Kong (primary school), and then at Saint John's University, Shanghai (high school) before moving to the United States to study architecture at the age of 18 at the University of Pennsylvania. He received a Bachelor of Architecture degree from Massachusetts Institute of Technology in 1940. He is a 1940 recipient of the Alpha Rho Chi Medal, the MIT Traveling Fellowship, and the AIA Gold Medal. He then studied at the Harvard Graduate School of Design. Shortly after his studies there, he was a member of the National Defense Research Committee in Princeton, New Jersey.

In 1944, he returned to Harvard, studying under Walter Gropius, who was previously associated with the Bauhaus. He received a Master's degree in Architecture in 1946. He was a member of the Harvard faculty subsequently attaining the rank of assistant professor. He received the Wheelwright Traveling Fellowship in 1951 and became a naturalized citizen of the United States in 1954

In 1948, William Zeckendorf hired Pei to work at the real estate development corporation Webb and Knapp in a newly created post, Director of Architecture. While at Webb and Knapp, Pei worked on many large-scale architectural and planning projects across the country and designed his buildings mostly in the manner of Ludwig Mies van der Rohe.

Pei founded his own architectural firm in 1955, which was originally known as I. M. Pei and Associates and, later, I. M. Pei & Partners until 1989 when it became known as Pei Cobb Freed & Partners recognizing James Ingo Freed and Henry N. Cobb.

I.M. Pei is a Fellow of the American Institute of Architects and a Corporate Member of the Royal Institute of British Architects. He has also been elected to the American Academy of Arts and Sciences, the National Academy of Design, and the American Academy and Institute of Arts and Letters.
In 1975 he was elected to the American Academy, which is restricted to a lifetime membership of fifty members. In 1978, he became Chancellor of the American Academy, the first architect to hold that position. He served until 1980. Mr. Pei was inducted a "Membre de l'Institut de France" in 1984, and decorated by the French government as a Commandeur in the "Ordre des Arts et des Lettres" in 1985.
On July 4, 1986, he was one of twelve naturalized American citizens to receive the Medal of Liberty from President Ronald Reagan. Two years later French president François Mitterrand inducted I. M. Pei as a Chevalier in the Légion d'Honneur. In November 1993 he was raised to Officier. Also in 1993, he was elected an Honorary Academician of the Royal Academy of Arts in London. In 1997 the Académie d'Architecture de France elected him Foreign Member.