Serratifusus sitanius is a species of sea snail, a marine gastropod mollusc in the family Austrosiphonidae. The name is said to derive from Latin word <nowiki/>'sitanius, meaning 'summer wheat'.
The length of the shell attains 61.4 mm.
This marine species occurs off New Caledonia (depth range: 600 âÂÂ616 m).