The Columbia University Mailman School of Public Health (formally the Joseph L. Mailman School of Public Health) is the public health graduate school of Columbia University. Located on the Columbia University Irving Medical Center campus in the Washington Heights neighborhood of Manhattan, New York City, United States of America, the school is accredited by the Council on Education for Public Health, and has been consistently ranked among the top ten schools of public health in the nation.

Founded in 1922 as the DeLamar Institute of Public Health, it is one of the oldest public health schools in the United States. It became an official school within Columbia University in 1945. In 1999, following a $33 million gift from the Mailman Foundation, the school was renamed the Joseph L. Mailman School of Public Health in honor of Joseph L. Mailman, an investor, philanthropist and founder of one of the earliest conglomerates in North America.

The school is home to the Calderone Prize, the most prestigious award in the field of public health, as well as numerous research centers, including the Center for Infection and Immunity, ICAP, the Robert N. Butler Columbia Aging Center, and the Center for Environmental Health Sciences in Northern Manhattan.