Alexander Fleming was born at Lochfield farm near Darvel in Ayrshire, Scotland. He was the seventh of eight children, and his parents were Hugh Fleming, a farmer, and Grace Stirling Morton.

Fleming received his early education at Loudoun Moor School and Darvel School. He excelled in mathematics and showed a keen interest in the natural world, reflecting his upbringing on a farm.

He attended Kilmarnock Academy, a larger and more academically rigorous school. Here he broadened his academic horizons and developed skills that were crucial for his later studies.

Fleming moved to London and attended the Polytechnic Institute. He initially worked in a shipping office for four years after arriving in London, an experience that gave him valuable life skills and exposed him to the bustling urban environment.

Fleming received a small inheritance from an uncle, John Fleming. This financial independence allowed him to pursue his ambition of studying medicine, which he had not been able to afford previously.

He enrolled at St. Mary's Hospital Medical School in London. It was through his membership in the Rifle Club that he was encouraged to join the research department at St Mary's, thus beginning his medical and scientific career.