Siddhartha Mukherjee (born 21 July 1970) is an Indian-American physician, biologist, oncologist, and author. He is best known for his 2010 book, The Emperor of All Maladies: A Biography of Cancer that won notable literary prizes including the 2011 Pulitzer Prize for General Non-Fiction, and Guardian First Book Award, among others. The book was listed in the "All-Time 100 Nonfiction Books" (the 100 most influential books of the last century) by Time magazine in 2011. His 2016 book The Gene: An Intimate History made it to #1 on The New York Times Best Seller list, and was among The New York Times 100 best books of 2016, and a finalist for the Wellcome Trust Prize and the Royal Society Prize for Science Books.

After completing school education in India, Mukherjee studied biology at Stanford University, obtained a D.Phil. from University of Oxford as a Rhodes Scholar, and an M.D. from Harvard University. He joined the faculty of medicine at the Columbia University Medical Center in New York City in 2009. As of 2018, he is an Associate Professor of Medicine in the Division of Hematology and Oncology.

Featured in the Time 100 list of most influential people, Mukherjee writes for The New Yorker and is a columnist in The New York Times. He is described as part of a select group of doctor-writers (such as Oliver Sacks and Atul Gawande) who have "transformed the public discourse on human health", and allowed a generation of readers a rare and intimate glimpse into the life of science and medicine. His research concerns the physiology of cancer cells, immunological therapy for blood cancers, and the discovery of bone- and cartilage-forming stem cells in the vertebrate skeleton.

The Government of India conferred him its fourth highest civilian award, the Padma Shri, in 2014.