Charles Stark "Doc" Draper (October 2, 1901 – July 25, 1987) was an American scientist and engineer, known as the "father of inertial navigation". He was the founder and director of the Massachusetts Institute of Technology's Instrumentation Laboratory, which was later spun out of MIT to become the non-profit Charles Stark Draper Laboratory.

Beginning in the 1940s, Draper developed inertial guidance systems for aircraft. In World War II, Draper invented the first lead-computing gunsights for aircraft, and later applying similar technology to missile guidance systems. In 1954, Draper's application of inertial controls to computerized autopilot allowed the Instrumentation Lab to conduct the first coast-to-coast unmanned flight. The lab also made the Apollo Moon landings possible through the Apollo Guidance Computer it designed for NASA. In 1960, Draper was one of the scientists recognized as Time magazine's Men of the Year.

Draper was born in Windsor, Missouri. He attended the University of Missouri in 1917, then transferred to Stanford University, California in 1919, from which he earned a B.A. in psychology in 1922. He matriculated at MIT in 1922, earning a Bachelor of Science degree in electrochemical engineering (1926), and Master of Science (1928), and a Doctor of Science (1938) degrees in physics. Charles Stark Draper's relatives were prominent in his home state of Missouri, including his cousin, Governor Lloyd C. Stark.

Draper began teaching at MIT as an assistant professor. He was appointed a full professor in aeronautical engineering in 1939. It was here that he founded the Instrumentation Laboratory in the 1930s, spun off in 1973 as the Charles Stark Draper Laboratory.

Draper's interest in flight instrumentation was influenced by becoming a pilot in the 1930s: although he failed to become an Air Corps pilot, he learned to fly by enrolling in a civilian course. Draper was one of the pioneers of inertial navigation, a technology used in aircraft, space vehicles, and submarines that enables such vehicles to navigate by sensing changes in direction and speed using gyroscopes and accelerometers. A pioneering figure in aerospace engineering, he contributed to the Apollo space program with his knowledge of guidance systems.

In 1961 Draper and the Instrumentation Lab were awarded the first contract given out for the Apollo program to send humans to the Moon, which was announced by President John F. Kennedy on 25 May of that year. This led to the creation of the Apollo Guidance Computer, a one-cubic-foot computer that controlled the navigation and guidance of the lunar module to the Moon on nine launches, six of which landed on the Moon's surface.

Draper taught and conducted research at MIT until January 1970, devoting most of his energy during his final decade to completing the Apollo computers and software.

Draper was inducted into the National Inventors Hall of Fame in 1981 for his multiple inventions and scientific contributions.