Muilenburg, who is 49 years old, currently serves as the aircraft company's executive vice president and president and CEO of its defense, space and security division.
Muilenburg was also named as vice chairman, along with Raymond L. Conner. The 58-year-old Conner was also promoted to president and CEO of the commercial airplanes unit. He's led the division since June 2012.
Fifty-three-year-old Christopher Chadwick is being named as Muilenburg's replacement at the defense, space and security division. Chadwick is currently president of the military aircraft unit, which will now be headed by Shelley Lavender.
The 49-year-old Lavender currently serves as vice president and general manager of integrated logistics for the global services and support business within the defense, space and security unit.
Boeing Co.'s stock rose 50 cents to $136.38 in Wednesday premarket trading.