John Hay Forbes, Lord Medwyn (19 September 1776 – 25 July 1854) was a British judge.
He studied law at Edinburgh University and was admitted to the Scottish Bar as an advocate in 1799.
In the 1830s he is listed as living at 17 Ainslie Place on the Moray Estate in the west end of Edinburgh.
He resigned that appointment in May 1849, retired from the bench in October 1852, and died in Edinburgh, 25 July 1854.
[citation needed] He edited a new edition of ‘Thoughts concerning Man's Condition and Duties in this Life, and his Hopes in the World to come’, by Alexander Forbes, 4th Lord Forbes of Pitsligo (1678–1762), 1835, 4th ed.