Gilbert Edmund Kaplan (March 3, 1941 – January 1, 2016) was an American businessman and financial publisher. He was also an aficionado of the music of Gustav Mahler, and an amateur conductor of Mahler's Symphony No. 2. 

Gilbert Kaplan is widely considered one of the foremost interpreters of Mahler's Second Symphony (Resurrection). He has conducted highly acclaimed performances of the work with more than 50 orchestras. He made his debut with the Orchestra of the Mariinsky Theatre in 1995 and in Russia has also led the St. Petersburg Philharmonic, Russian National Orchestra, State Academic Symphony Orchestra of Russia, Moscow State Symphony, Novosibirsk State Opera & Ballet Orchestra and Moscow Philharmonic.

Other performances include the New York Philharmonic, Vienna Philharmonic, Deutsche Oper Berlin, Bayerische Staatsorchester and Symphonieorchester des Bayerischen Rundfunks. In Great Britain, London Symphony, Philharmonia, Royal Philharmonic. In the United States, Los Angeles Philharmonic, Pittsburgh Symphony and National Symphony (Washington, D.C). Philharmonic Orchestra of La Scala, Royal Stockholm Philharmonic, Budapest Symphony, Prague Symphony, New Japan Philharmonic, Israel Philharmonic, Melbourne Symphony and the China National Symphony (in the premiere of Mahler's Second Symphony in China).
Mr. Kaplan’s recording of Mahler’s Second Symphony with the London Symphony Orchestra, with sales in excess of 180,000 copies, is the best-selling Mahler recording in history and was selected as one of the “Records of the Year” by The New York Times. His award-winning recording of Mahler’s Second Symphony with the Vienna Philharmonic has been the best-selling recording of the Second Symphony since it was released in 2003 by Deutsche Grammophon.

A leading authority on the composer, Mr. Kaplan is the author and editor of the illustrated biography The Mahler Album. His extensive writings on Mahler have appeared in publications ranging from London’s musicological journal The Musical Times to the The New York Times. On radio, he has served as the host of a 13-week Mahler series broadcast in the United States and for the past twelve years Mad About Music, a celebrity classical music and interview program.

Gilbert Kaplan is co-editor of the New Critical Edition of Mahler’s Second Symphony. The new edition, which contains hundreds of corrections, is published by Universal Edition and the Kaplan Foundation. Together with Rob Mathes, Mr. Kaplan has also created an arrangement of Mahler’s Second Symphony for small orchestras. It is that arrangement that will be performed at the 2014 Stars of the White Nights Festival.
A faculty member of the Juilliard School, Mr. Kaplan has also lectured at Harvard and Oxford universities and leading musical conservatories. He is a recipient of many honors, including an honorary Ph.D. from Westminster Choir College of Princeton, New Jersey, and serves on the boards of many cultural institutions, including Carnegie Hall and the the Department of Music at Harvard University.