Robert Isaacson (1 September 1927, St. Louis, Missouri – 5 November 1998, New York City) was a collector, scholar, and art dealer eulogized upon his death as "the Berenson of nineteenth century academic studies."
An only child, Isaacson's personal fortune derived from his maternal grandmother, whose family found success in the fur trade; Isaacson spent early summers surrounded by aunts, uncles, and family retainers in his grandmother's ornate mansion in Leavenworth, Kansas. Despite an apparent reading disability, Isaacson was musically gifted; he was permitted to move alone at age sixteen from Saint Louis to New York City to study the harpsichord, although his only subsequent education in any organized sense was a summer at Black Mountain College.
Isaacson spent several years in post-war Rome, Florence and Venice exploring churches and museums, developing a formidable and deeply intuitive understanding of painting, drawing, and the evolution of artistic temperament. In Rome in the early 1950s, Isaacson dated the poet James Merrill, who wrote candidly about their relationship in his 1993 memoir, A Different Person. The couple visited Istanbul together—the visit proved a formative experience in Merrill's career—and the two men remained close friends until the poet's death in 1995.
Upon Isaacson's return to New York, he became an art dealer almost by accident, taking on Edwin Hewitt's gallery at the request of mutual friend Lincoln Kirstein. Although the Robert Isaacson Gallery, located at 22 East 66th Street, represented the estate of Elie Nadelman and championed Magic Realist painters (including his favorite, George Tooker), Isaacson's growing interest and fascination with nineteenth century academic painting, an extremely unfashionable pursuit in the 1950s, would in time make him the paradigm of the scholarly dealer: his opinions and near-encyclopedic knowledge of the once-obscure field were sought long after the Robert Isaacson Gallery shut its doors (around 1970) and Isaacson began devoting himself full-time to curating and collecting. Isaacson played an important role in helping rehabilitate the reputations of Lawrence Alma-Tadema, Charles Bargue, William-Adolphe Bouguereau, Thomas Dewing, Jean-Léon Gérôme, Albert Joseph Moore, Mihály Munkácsy and Gaston La Touche, among others.
In keeping with Isaacson's will, thirteen important paintings from his collection (including five Gérômes) were auctioned by Christie's on 6 May 1999 to benefit a charitable foundation. Records for the Robert Isaacson Gallery (1952–67), Hewitt Gallery, Durlacher Bros. and related business and exhibition papers are on deposit with the Smithsonian Institution.
- Draper, James David (biographical essay). The Age of Elegance & Barbizon, Realist and French Landscape Paintings Including Important Paintings from the Collection of Robert Isaacson - Christie's, New York - 6 May 1999 - Sale #9152/9202, Christie's New York, Thursday 6 May 1999.
- Merrill, James. A Different Person: A Memoir. New York: Alfred P. Knopf, 1993.
- Merrill, op. cit., Chapter XIX, pp. 233-245. "It had been a folly to dream of seeing Istanbul in two days, yet a brief impression was better than none [...]"
- An Exhibition to Commemorate the 50th Anniversary of the Death of Sir Lawrence Alma-Tadema, 1836-1912. New York: Robert Isaacson Gallery, 1962.
- Isaacson, Robert. William-Adolphe Bouguereau (catalogue). New York Cultural Center and Farleigh Dickinson, 1974.
- Isaacson, Robert. Jean-Léon Gérôme and his pupils. Poughkeepsie, New York: Vassar College Art Library, 1967.
- Grace Glueck (November 19, 1998). "Robert Isaacson, 71: Dealer in French, English Art". The Day. New London. New York Times News Service. pp. B8. Retrieved 2013-05-29.
- Smithsonian Institution Libraries. Robert Isaacson search, accessed 25 May 2013.
- Smithsonian Institution, Archives of American Art. Robert Isaacson Gallery Records, 1952–1967, accessed 25 May 2013.
- New York Times, Robert Isaacson, Paid Death Notice, 8 November 1998, accessed 25 May 2013.