Samantha Hayes, 27, was riding the mower on the grass at Broken Bow Airport, a small airport 170 miles northeast of Dallas, on Friday afternoon.
At the time, pilot James Baxter, 70, was also preparing to land his 1972 Bananza A36 on the runway, reported KFOR.
Oklahoma Highway Patrol said Mr Baxter spotted Hayes riding the mower and quickly tried to manoeuvre the craft to avoid hitting her but was unable to do so.
The wing of the plane clipped Hayes in the head.
The 27-year-old was pronounced dead at the scene.
It is currently unclear if she worked at the rural airport or why she was riding a lawnmower there at the time of the tragedy.
She has since been remembered by friends as a hardworking and devoted mother.
“Samantha Hayes was a wonderful great mom to her three babies,” one person wrote on Facebook.
“She was a single mom who worked hard to give them a safe and loving home! These babies knew they were loved everyday all day!”
“We never know when these things are gonna happen but they can and for her it did.”
No charges have been filed against Mr Baxter but the incident remains under investigation.
The Independent has reached out to the Oklahoma Department of Public Safety for further comment.