Robert Neil Butler (born January 21, 1927) is a physician, gerontologist, psychiatrist, and Pulitzer Prize-winning author, who was the first director of the National Institute on Aging. Butler is known for his work on the social needs and the rights of the elderly and for his research on healthy aging and the dementias.
Having grown up with his grandparents,  Butler was shocked by the dismissive and contemptuous attitude toward the elderly and their diseases by many of his teachers at medical school, an attitude he later characterised as "ageism." 
Butler was a principal investigator of one of the first interdisciplinary, comprehensive, longitudinal studies of healthy community-residing older persons, conducted at the National Institute of Mental Health (1955-1966), which resulted in the landmark book Human Aging. His research helped establish the fact that senility was not inevitable with aging, but is a consequence of disease.
In 1975, he became the founding Director  of the National Institute on Aging (NIA) of the National Institutes of Health, where he remained until 1982. At the National Institute on Aging he established Alzheimer's Disease as a national research priority.
In 1982, he founded the Department of Geriatrics and Adult Development at The Mount Sinai Medical Center, the first department of geriatrics in a United States medical school. In addition, Butler helped found the Alzheimer's Disease Association, the American Association of Geriatric Psychiatry, the American Federation for Aging Research and the Alliance for Aging Research.
Butler is the founder, Chief Executive Officer, and President of the International Longevity Center-USA, a non-profit international organization created to educate people on how to live longer and better. 
Butler is best known for his 1975 book Why Survive? Being Old In America, which won the Pulitzer Prize for General Non-Fiction in 1976. A 2003 paperback edition is currently available (ISBN 0-8018-7425-4). Other recent books by Butler include Aging and Mental Health: Positive Psychosocial and Biomedical Approaches (with Myrna I. Lewis and Trey Sunderland, 1998), Life in an Older America (2001) (ISBN 0-87078-438-2), and The New Love and Sex After 60 (with Myrna I. Lewis, 2002) (ISBN 0-345-44211-3).
Butler was the recipient of the 10th Annual Heinz Award in the Human Condition category.  The award recognizes his work in advancing the rights and needs of the nation's aging citizenry and enhancing the quality of life for elderly Americans.
He has received honorary degrees from the University of Gothenburg in Sweden and the University of Southern California as well as other awards such as the Lienhard Medal of the Institute of Medicine and a Hall of Fame Award from the American Society of Aging. 
He is featured in the 2009 documentary film I Remember Better When I Paint which looks at the positive impact of art on people with Alzheimer's and how these approaches can change the way people look at the disease.