Argyropelecus sladeni, or Sladen's hatchetfish, is a species of ray-finned fish in the family Sternoptychidae, found in the tropical and subtropical Atlantic, Indian and Pacific Oceans.

Argyropelecus sladeni is a small, deep-bodied hatchetfish with an abdominal keel and a maximum standard length of about 60 mm (2.4 in).

The mouth is of medium size, the tubular eyes point upwards, the dorsal fin has nine soft rays and is three times as long as it is high, and the adipose dorsal fin has a long base.

The dorsal surface of the fish is dark, the flanks are silvery and there are photophores (luminous spots) on the operculum and belly.

[5] Argyropelecus sladeni feed on planktonic organisms, krill, amphipods, copepods and ostracods.