Thomas Cadwalader (1707–1779) was an American physician in Philadelphia. After studying medicine with his uncle Dr. Evan Jones, he traveled to London to study medicine were he was an understudy of William Cheselden. In France he probably attended lectures at Rheims University. He lived for a while near Trenton, New Jersey, where he became the chief burgess in 1746. After returning to Philadelphia, he was elected in 1751 to the city's Common Council. He served on Pennsylvania's Provincial Council from 1755 until the Revolution. He was one of the founders of the Pennsylvania Hospital in 1751. Dr. Cadwalader was one of the first to inoculate patients against smallpox He was a founder and director of the Library Company of Philadelphia and a member of the American Philosophical Society.
His sons, John and Lambert were active in the American Revolutionary War.
Cadwalader Park, in Trenton, New Jersey, was named in his honor. The park has an area of nearly 100 acres (0.40 km2), and was designed by Frederick Law Olmsted and built starting in 1887.