Clarias insolitus is a catfish within the genus Clarias, found in the upper drainage of the Barito River, in Kalimantan, Indonesian Borneo.

Specific habitat details have not been mentioned .

[2] Collected as recent as 1991, the holotype length was 122.5 mm (or 4.8 inches) in SL, with 7 paratypes collected from the same area ranging from 53.5 to 139.7 mm (2.1-5.5 inches), though it hasn't been inferred about the specimen's matuirty status.

The diagnosis has been defined by:[2] It is further distinguishable from other clariids from the following characteristics (except for C. intermedius, C. meladerma, C. olivaceus, and C. planiceps): Further characteristics include: Coloration has been noted to be violet-gray (or plum) in lateral and dorsal areas, with dorsal, anal and pectoral fins with the same coloring, sometimes ranging to translucent near margins.

Barbels are violet-gray dorsally, yet paler ventrally (about light gray).