William E. Boeing, Jr. (November 22, 1922 – January 8, 2015) was the son of aviation pioneer William Edward Boeing, founder of the Boeing Company. Boeing Jr. was a real estate developer, philanthropist and former member of the Seattle Museum of Flight board of trustees. In 2010, the American Institute of Aeronautics and Astronautics presented Boeing Jr. with a certificate of achievement for his commitment to education and the preservation of air and space history.

Boeing, Jr. had fond childhood memories of the Red Barn, the birthplace of the Boeing Company, where he was once given a piece of balsa wood he crafted into a model ship. But he did not understand his father's importance until his classmates nicknamed him after one of the Boeing airplanes. In the late 1970s he was instrumental in ensuring that the Red Barn, the oldest airplane manufacturing facility in the U.S., was preserved and integrated into the Seattle Museum of Flight.]He died in Seattle at the age of 92 on January 8, 2015