The exact source of the word "Monticello" (pronounced "Monti-cello," like the musical instrument) as the name for Thomas Jefferson's plantation home remains a mystery. Jefferson's earliest documented use of the word appears in his garden book entry of August 3, 1767: "inoculated common cherry buds into stocks of large kind at Monticello."^[1] Yet just two years later, in his account book, Jefferson records that 9,787 pounds of tobacco were made at "Moncello" in 1768.^[2] Later, in a January 1770 entry, Jefferson notes "work to be done at Hermitage," but at some point, he crosses Hermitage out and writes in Monticello.^[3] After this last entry, Jefferson consistently refers to his property as Monticello; however, because these early entries may have been made retroactively, it is impossible to pinpoint exactly when Jefferson began to use the name.

Since Monticello means "hillock" or "little mountain" in Italian, there is a logical explanation for Jefferson's choice. Jefferson may have just translated the names of the two mountains as they appeared in the Albemarle County Deed Books — Little Mountain and High Mountain — into Italian. High Mountain was referred to by Jefferson as Montalto, which he acquired in 1777. Jefferson's interest in Italian began as early as 1764 when he purchased an Italian-English dictionary, two historical works in Italian, and the works of Machiavelli. By 1767, Jefferson had also convinced Francesco Alberti, a musician from Faenza, to move into the area so that he could study the violin with him.

Another source may have been Andrea Palladio's Four Books of Architecture, a work Jefferson deemed to be his "bible." In Book One of the 1721 Leoni translation, Palladio describes the ideal setting for a country house, his famous Villa Rotonda near Vicenza: "Its situation is as advantageous and delicious as can be desired, being seated on a hillock of a most easy ascent ...."^[4] This was cited in Jefferson's account books of the 1770s. Whether or not Jefferson read this in Italian at this early date is unclear, but it is a possibility. At least the theater-like description of the site, located on top of a hillock above a navigable river and surrounded by hills and orchards, must have influenced Jefferson.

Although the name "Monticello" has been used elsewhere in the United States and its pronunciation usually Americanized to "Montisello," there is abundant evidence to indicate that Jefferson himself used the Italian pronunciation of "Monticello" for his mountaintop home. For example, in 1781 George Gilmer wrote to Jefferson, "I long to behold the period when you may with propriety retreat to Montchello ..."^[5] In 1789, Baron Geismar wrote to Jefferson, "Que je Vous envie Votre Retour à MontiChello, Sejour paisible et agreable que j'y ai passé!"^[6] In 1805, Meriwether Lewis wrote to Jefferson from Fort Mandan, "You may therefore expect me to meet you at Montochello in September 1806."^[7] A visitor in 1823 wrote, "It is pronounced Montichello giving the C the Italian sound of CH soft."^[8] And in 1843, James Adams Kasson, a newcomer to Albemarle County who became acquainted with a member of the Jefferson family, wrote: "I am working my way around ... into most of the families of this circle which contains, besides those I have before mentioned, a gentleman closely related to Jefferson and brought up at Monticello (President J.'s seat), the 'c' pronounced like 'ch' in chair – 'Montichello.'"^[9]

- Rebecca Bowman, May 1996; references added by Anna Berkes, April 23, 2012