Sir John Pirie, 1st Baronet (1781 – 26 February 1851), was a British shipbroker and Lord Mayor of London. He was the largest shipbroker in London. In the 1830s he started to uphold Wakefield's principles and became a founding director, and one of the largest financiers, of the South Australian Company. He was also a director of the New Zealand Company, and the East India Company. One of the first three ships despatched in 1836 to found the new colony of South Australia was the 105-ton two-masted schooner named John Pirie.