Gasterosteus is a genus of ray-finned fishes belonging to the family Gasterosteidae in the suborder Gasterosteoidei. These fishes are found in freshwater, brackish water and marine habitats in the Holarctic region.

• Gasterosteus aculeatus Linnaeus, 1758 (Three-spined stickleback)
• †Gasterosteus crenobiontus Băcescu & R. Mayer, 1956 (Techirghiol stickleback)
• Gasterosteus islandicus Sauvage, 1874 (Iceland stickleback)
• Gasterosteus microcephalus Girard, 1854 (Smallhead stickleback)
• Gasterosteus nipponicus Higuchi, Sakai & A. Goto, 2014
• Gasterosteus wheatlandi Putnam, 1867 (Black-spotted stickleback)

• †Gasterosteus kamoensis Nazarkin, Yabumoto & Urabe, 2013

• Obolarius Tilesius, 1811
• Gasteracanthus Pallas, 1814
• Leiurus Swainson, 1839
• Gladiunculus Jordan & Evermann, 1927

1. Higuchi, M., Sakai, H. & Goto, A. (2014): A new threespine stickleback, Gasterosteus nipponicus sp. nov. (Teleostei: Gasterosteidae), from the Japan Sea region. Ichthyological Research, (61) 4: 341-351.
2. "Gasterosteus aculeatus". Animal Diversity Web.
3. Froese, Rainer; Pauly, Daniel (eds.) (2022). "Gasterosteus wheatlandi" in FishBase. August 2022 version.
4. Freyhof, J. & Kottelat, M. (2008). "Gasterosteus crenobiontus". IUCN Red List of Threatened Species. Retrieved 15 November 2021.