Sinclair Weeks was secretary of commerce under President Eisenhower from January 21, 1953, to October 22, 1958. Weeks graduated from Harvard with a B.A. in 1914 and started work as a banker in Boston.

In 1916, he joined the National Guard and was sent to Mexico; he then enlisted in the Army and fought in Europe during the First World War, becoming a captain before being discharged in 1919. Weeks returned to banking and then switched to the metal manufacturing business in 1923. He served Newton, Massachusetts, as alderman (1923-1930) and later as mayor (1930-1935).Active in Republican Party politics, Weeks was chairman of the Republican State Committee (1936-1938), member of the Republican National Committee (1941-1953), and treasurer of the party (1941-1944). After having lost the Republican nomination for the U.S. Senate to Henry Cabot Lodge in 1936, Governor Leverett Saltonstall appointed Weeks to serve out the remainder of Lodge's term, which was vacant due to Lodge volunteering for the Army, from February 8, 1944, to December 1945; Weeks did not seek reelection to the position, however.

Eisenhower offered Weeks the job of chairman of the Republican National Committee after Weeks's fight for his nomination in 1952. Instead, Weeks sought the position at Commerce in order to put his business philosophy to work in government.

As secretary, he convinced Eisenhower to drop all wage and price controls introduced by the Truman administration. Weeks clashed repeatedly with Secretary of Labor Martin Durkin over sections of the Taft-Hartley Act that unions had opposed. After enlisting Vice President Richard Nixon in his defense, Weeks prevailed, and the conflict prompted Durkin's resignation.

Weeks also oversaw the renegotiation of the General Agreement on Tariffs and Trades (GATT) and a massive building program of merchant ships. After his stint in government, he became director of the First National Bank of Boston and, in 1964, joined Hornblower and Weeks-Hemphill, Noyes investments company as a partial partner. He remained with the firm until just before his death in 1972. His father was John Wingate Weeks, secretary of war under Presidents Warren G. Harding and Calvin Coolidge.