In 1917, the Mellor family moved to Wichita, Kansas where she skipped high school and began attending the American Secretarial and Business College.

[2] In 1925, at the age of 21, she was hired by Clyde Cessna and took a job as an office secretary and bookkeeper for the newly formed Travel Air Manufacturing Company in Wichita.

[11][1][2][3] Olive Ann worked with the financial side of the business and played an important role in major company decisions.

Olive Ann suggested that to help increase sales of the aircraft the company should sponsor a woman pilot flying the Staggerwing in the 1936 transcontinental Bendix Trophy Race.

[3] In 1940, Walter became ill with encephalitis and Olive Ann took over the leadership of the company at a time when retooling was required for military production of both the Staggerwing and the Twin Beech.

Beech Aircraft took steps to support the United States' space exploration efforts during the late 1950s with the development of cryogenic systems for NASA.

[3] In response to the introduction of crosstown Wichita rival Bill Lear's successful Learjet in 1964, Olive Ann decided that Beechcraft should produce a turboprop version of the Queen Air instead of a jet.

Asked by a reporter for Forbes magazine when Beechcraft would be producing a jet, Beech replied "We will, when it is compatible with our other activities.

[13][14] Although piston aircraft sales for Beechcraft were at record highs during the 1960s, her policy would affect the company's late entry into the jet market.

Due to lackluster sales in the aircraft industry, in 1982 Raytheon reorganized several divisions and removed Beech and Hedrick from the board of directors of Beechcraft and gave her the title of chairman emeritus.

[26] In 2013, Beech was listed, along with her husband Walter, as one of Flying Magazine's 51 Heroes of Aviation, ranking at number 31.

[4] In 2023, Beech was inducted, along with her husband Walter, into the Paul E Garber First Flight Shrine in Kill Devil Hills, NC.