Thorvald Mejdell (21 September 1824 – 28 October 1908) was a Norwegian forester.
He was born in Ringsaker as a son of colonel Gløer Gløersen Mejdell (1782–1827) and Thorine Krog.
He was a nephew of officer Jacob Gerhard Meydell and brother of mining engineer Nicolai Mejdell,[1] and an uncle of jurist and writer Glør Thorvald Mejdell.
He was a forest manager at Kongsberg Silver Works from 1848 to 1852, then studied forestry in Tharandt for three years before being hired as an adviser in the Ministry of Industry in 1855.
From 1875 to 1892 he worked in the private company Kiær & Co.[1] He did not marry, and died in October 1908 in Kristiania.