Tord Tamerlan Teodor Thorell (3 May 1830 - 22 December 1901) was a Swedish arachnologist.Thorell studied spiders with Giacomo Doria at the Museo Civico di Storia Naturale de Genoa. He corresponded with other arachnologists, such as Octavius Pickard-Cambridge, Eugène Simon and Thomas Workman.He described more than 1,000 spider species during his time from the 1850 to 1900.Thorell wrote two significant works: On European Spiders (1869) and Synonym of European Spiders (1870-73).