Nils Johan Andersson (20 February 1821 Gärdserum, Småland, Sweden – 27 March 1880 Stockholm), was a Swedish botanist and traveller.

On 30 September 1851 he accompanied the Swedish expedition as botanist aboard the frigate HSwMS Eugenie, sailing from Karlskrona under the command of Captain Christian Adolf Virgin (1797-1870),[2] on the first Swedish circumnavigation, calling at Honolulu, Tahiti, San Francisco, Sydney and Manila, various South American ports, the Galapagos, Hong Kong and Singapore.

His special interests were Salix, Cyperaceae and Gramineae and he published numerous papers on the systematics and morphology of these taxa.

Kortfattad anvisning att ingenkänna, insamla och till födoämne bereda några af våra allmännaste lafvar.

[4] In 1875, acting on behalf of the Swedish Museum of Natural History, he acquired Sonder's South African collection of some 100 000 specimens.