From 1696 until his death in 1727, Isaac Newton worked at the Royal Mint, first as Warden (to 1699) and then as Master. He played a vital role in major economic and financial events such as the Great Recoinage (1696-99), the amalgamation of the English and Scottish mints (1706-7), the fixing of the value of the guinea in 1717, and the fall-out from the South Sea Bubble of 1720. This paper uses Newton’s employment at the Mint to explore the wide-ranging intersections between monetary history and the history of science in the first half of the eighteenth century. It examines how he handled various practical aspects of money-making, from metallurgy and metrology to the management of artisanal workers and the improvement of machines. Finally, it places these activities within broader commercial and bureaucratic contexts.