Caroline Carmichael McIntosh Fillmore (October 21, 1813 – August 11, 1881) was the second wife of 13th U.S. PresidentMillard Fillmore. They were married in 1858, five years after his term of office expired.

Caroline Carmichael was born October 21, 1813 in Morristown, New Jersey, the daughter of Charles Carmichael and Temperance Blachley Carmichael. She married her first husband, Ezekiel C. McIntosh (1806–1855), a prosperous Troy, New York merchant and president of the Schenectady and Troy Railroad, in November 1832. They had no children, and McIntosh's death at age 49 left her very wealthy.

She married Millard Fillmore on February 10, 1858 in Albany, New York. At the time of their marriage, Caroline required Fillmore to sign a prenuptial agreement. The couple purchased a mansion on Niagara Square in Buffalo, where they settled. They are believed to have had a happy marriage (Caroline greatly enjoyed her newfound status as the wife of a former President), though in the 1860s her mental and physical health began to decline. Her husband's sudden death in 1874 (he had enjoyed relatively good health—especially when compared to hers—until just shortly before his fatal stroke) only succeeded in making her more infirm, eccentric, and temperamental.

In her final years she frequently changed her will, and upon her death on August 11, 1881, aged 67, suits were initiated by various members of the Fillmore family contesting her directives.

She is buried in the Fillmore family plot at Forest Lawn Cemetery in Buffalo.