Who created Apollo 11?

Apollo 11 was a NASA program, not the project of a single inventor, and its hardware came out of factories spread across half of North America. The spacecraft itself had three parts. The command module Columbia, the conical capsule that was the only part to return to Earth, was built by North American Rockwell; it was attached to the service module, which carried the main propulsion and consumables. The lunar module Eagle was designed by Grumman: a two-stage vehicle for two crew members, with the landing gear, descent engine, and experiments in the lower stage, and the pressurized cabin and ascent engine in the upper stage.

The Saturn V was divided among three prime contractors, one per stage. Boeing built the first, the S-IC, at the Michoud plant in New Orleans; North American Aviation built the second, the S-II, in Seal Beach, California; and Douglas Aircraft the third, the S-IVB, in Huntington Beach. IBM designed and built the instrument unit, the ring containing the avionics that governed the whole stack, in Huntsville, Alabama. Overall design direction rested with the Marshall Space Flight Center in Huntsville, with Wernher von Braun leading the technical team and George Mueller overseeing the program.

That list of names explains why the question has no individual answer. What made Apollo 11 possible wasn't an invention but a management architecture capable of integrating parts built by rival companies, with interfaces defined down to the millimeter and responsibilities spread across NASA centers. The division by stage itself, with a different company for each section of the rocket, was as much an industrial engineering decision as a technical one: it allowed parallel work and avoided dependence on a single supplier.