He was born in Grand Rapids, Michigan and earned a B.S. in aeronautical engineering from Purdue University in 1957. He was married with two children.
He was chosen in the third group of astronauts in 1963 and had made no spaceflights before being selected as lunar module pilot for the first Apollo program flight.
Chaffee died along with fellow astronauts Gus Grissom and Edward White in the Apollo 1 fire at Cape Kennedy.