William Fleming (1799 – 1880) was a British physician and antiquary.
He obtained his Doctor of Medicine (MD) degree and practiced as a physician in Manchester for many years.
He was elected a Member of the Manchester Literary and Philosophical Society in 1828.
He was a founding Member of the Chetham Society and served as its first Secretary from 1843 to 1852.
His archives were bequeathed to the Medical Collections at the University of Manchester Library.