Crews were called out to the well in Strensall, near Haxby, after reports that the woman in her 60s was trapped at about 6.15pm yesterday (Wednesday).
When firefighters arrived, she was standing at the base of the well, waist-deep in water, North Yorkshire Fire and Rescue Service said.
They used a triple-extension ladder to help her climb out.
She was given first aid for a head injury until paramedics arrived at the scene.