:Hyposulfite

{{distinguish|text=hydrosulfite, which is another name for the dithionite anion ({{chem|S|2|O|4|2−}})}}

Hyposulfite may refer to:

• The sulfoxylate anion ({{chem|S|O|2|2−}})
• The thiosulfate anion ({{chem|S|2|O|3|2−}})
• Sodium thiosulfate, a salt containing the thiosulfate anion
• {{chem|S|2|O|2|2−}}, a reported sulfur oxyanion. However salts containing {{chem|S|2|O|2|2−}} and {{chem|HS|2|O|2|−}} are not well characterized; they would be conjugate bases derived from the parent thiosulfurous acid ({{chem|H|2|S|2|O|2}}), which is also of doubtful existence.{{Greenwood&Earnshaw}}
• Dithionite ({{chem|S|2|O|4|2−}}) as in sodium dithionite.{{cite journal|doi=10.1021/ed066p359.2|bibcode=1989JChEd..66..359W|title=Reduction of Indigo: Sodium Hydrosulfite as a Reducing Agent|year=1989|last1=Williamson|first1=Kenneth L.|journal=Journal of Chemical Education|volume=66|issue=4|pages=359|doi-access=free}}