Alfred Gabriel Nathorst was born on November 7, 1850, in Väderbrunn, Södermanland County, Sweden.

He was a Swedish Arctic explorer, geologist, and paleobotanist. He was educated at Malmö and entered the University of Lund in 1868. In 1871, he enrolled at the University of Uppsala but returned to Lund, where he got his doctorate in 1874. From 1873 to 1884, he worked at the Geological Survey of Sweden. In 1884, he was appointed professor at the Swedish Museum of Natural History, remaining at this position until his retirement in 1917. He participated in several expeditions (Spitsbergen, 1871; Bear Island and Svalbard, 1898, and Greenland, 1899). Nathorst investigated postglacial development in flora and vegetation. He also researched the plant remains from older geological eras, such as Paleozoic and Mesozoic from the Arctic and tertiary from Japan. These investigations made him an internationally acknowledged authority on paleobotany. In 1885, he was elected member of the Royal Swedish Academy of Sciences. A number of plant, animal, and fungal species have been named in his honour, e.g., Saxifraga nathorstii (Dusén) Hayek, Williamsonia nathorstii Carruthers (a fossil dragonfly), and Laestadites nathorstii Mesch. He published numerous books and articles related to his research in Swedish, English, German, and French.

In 1878, he married Amelie Rafaela (Ella) Windahl (1858–1936). He died on January 20, 1921, in Stockholm, Sweden.