It ultimately derives from Ancient Greek osmé (ὀσμή, "pungent smell") + Latin forma ("external form"), the former in reference to the characteristic aroma of the flesh of Osmerus.

Other authors choose a slightly different arrangement, but whether treated as suborders (Galaxoidei and Osmeroidei) or superfamilies (Galaxoidea and Osmeroidea), the division in two lineages is generally maintained.

[4][5] The "marine" smelts and allies (e.g. the odd-looking barreleyes) were formerly included here as suborder Argentinoidei; they are now usually considered more distantly related than it was believed and treated as order Argentiniformes.

[3][4] The oldest definite osmeriform is Speirsaenigma from the Paleocene of Alberta, Canada, which was a relative of the modern ayu fish and appears to have been a freshwater species.

[7][8] The families Galaxiidae and Lepidogalaxiidae were at one time placed together with Retropinnidae in the sub order Galaxoidei, however with new molecular studies they have been elevated to the ordinal level.