Bernard Berenson (June 26, 1865 – October 6, 1959) was an American art historian specializing in the Renaissance. He was a major figure in pioneering art attribution and therefore establishing the market for paintings by the "Old Masters".

Berenson was born Bernhard Valvrojenski in Butrimonys (now in Alytus district of Lithuania) to a Litvak family. They emigrated to Boston, Massachusetts from the Vilna Governorate of the Russian Empire in 1875, whereupon the family name was changed to "Berenson."  He attended the Boston University College of Liberal Arts as a freshman during 1883-84, but, unable to obtain instruction in Sanskrit from that institution, transferred to Harvard University for his sophomore year.  He graduated from Harvard and married Mary Smith, who became a notable art historian in her own right.

Among US collectors of the early 1900s, Berenson was regarded as the pre-eminent authority on Renaissance art. His verdict of authenticity increased a painting's value. While his approach remained controversial among European art historians and connoisseurs, he played a pivotal role as an advisor to several important American art collectors, such as Isabella Stewart Gardner, who needed help in navigating the complex and treacherous market of newly fashionable Renaissance art. As Renaissance scholarship has evolved, a number of Berenson's attributions are now believed to be incorrect. There is also ongoing speculation as to whether some of these misattributions were deliberate, since Berenson often had a considerable financial stake in the matter. Due to the strong subjective element in connoisseurship, such accusations remain hard to either disprove or substantiate.  Berenson died at age 94 in Settignano, Italy.