Roderick Edward Maclean (c. 1854 – 8 June 1921) was a Scotsman who attempted to assassinate Queen Victoria on 2 March 1882, at Windsor, England, with a pistol.

A number of Eton boys were round the station at the time, and one of them rushed forward and struck Maclean with his umbrella, disconcerting his aim — which was unlikely enough, in any case, to have been accurate.

– Lichfield Mercury, 1921[6]At his trial, Dr. Charles Vernon Hitchins testified that MacLean had been certified insane in June 1880, two years before the attempted assassination, and he had been sent to Somerset Lunatic Asylum.

"[1] Tried for high treason on 20 April, Maclean was found "not guilty, but insane" by a jury after five minutes' deliberation, overseen by Lord Chief Justice Coleridge, and he lived out his remaining days in Broadmoor Asylum.

The verdict prompted the Queen to ask for a change in English law so that those implicated in cases with similar outcomes would be considered as "guilty, but insane"; this led to the Trial of Lunatics Act 1883.