Per Johan Alström (born 9 April 1961) is a Swedish Professor of ornithology.
He researches in taxonomy, systematics, and evolution, with birds in Asia as a specialty.
Alström works at the Department of Ecology and Genetics (Animal Ecology) at Uppsala University and at the Swedish Species Information Centre at the Swedish University of Agricultural Sciences, Uppsala.
He has previously worked as e.g. Curator of Ornithology at the Swedish Museum of Natural History, and been a guest researcher at the Percy Fitzpatrick Institute of African Ornithology, University of Cape Town and a visiting professor at the Chinese Academy of Sciences, Beijing.
Deputy Editor-in-Chief of the international ornithological journal Avian Research.