NASA Astronaut Group 6 was a group of eleven astronauts announced by NASA on August 11, 1967, the second group of scientist-astronauts. Although Director of Flight Crew Operations Deke Slayton planned to hire 20 to 30 new scientist-astronauts, he did not expect any to fly because of a surplus of astronauts amid the looming dearth of post-Apollo program funding, exemplified by the concomitant devolution of the Apollo Applications Program into the Skylab Program. NASA found that only 11 of the 923 applicants were qualified, and hired all.

Donald Kent "Deke" Slayton was an American Air Force pilot, aeronautical engineer, and test pilot who was selected as one of the original NASA Mercury Seven astronauts. He went on to become NASA's first Chief of the Astronaut Office and Director of Flight Crew Operations, responsible for NASA crew assignments.