J
- François Jacob (born 1920), French Biologist, Nobel Prize
- Nikolaus Joseph von Jacquin (1727–1817), Dutch-born Austrian botanist
- Honoré Jacquinot (1815–1887), French surgeon and zoologist
- Daniel H. Janzen (born 1939), American entomologist and ecologist
- William Jardine (1800–1874), Scottish naturalist
- Feliks Pawel Jarocki (1790–1865), Polish zoologist
- Thomas C. Jerdon (1811–1872), British zoologist and botanist
- Wilhelm Johannsen (1857–1927), (coined the term gene)
- David Starr Jordan (1851–1931), ichthyologist, 1st president of Stanford
- Félix Pierre Jousseaume (1835–1921), French zoologist and malacologist
- Adrien-Henri de Jussieu (1797–1853), French botanist
- Antoine de Jussieu (1686–1758), French naturalist
- Antoine Laurent de Jussieu (1748–1836), botanist, biologist (abbr. in botany: Juss.)
- Bernard de Jussieu (1699–1777), French naturalist
- Ernest Everett Just (1883–1941), American biologist
Read more about this topic: List Of Biologists