Siksika ottae is an extinct species of petalodont (a type of prehistoric cartilaginous fish), which lived during the Upper Mississippian.

It has been discovered at the well known Carboniferous-aged Bear Gulch Limestone (Montana, United States).

It is known primarily from fossil teeth, but also from partial neurocranium and mandibles which hint at a close relationship to coeval petalodontiforms such as Janassa and Netsepoye.

Dentition is generally heterodont.

This article about a prehistoric holocephalan is a stub.