There is provided an apparatus and method of filleting and cleaning a cephalopod, including squid. The apparatus for use in filleting a cephalopod including, a body having a first end being shaped for insertion into a cavity of a mantle of the cephalopod and a second end graspable by a user, a cutting member located at, or adjacent, the first end, for severing an internal membrane of the cephalopod, a guide located adjacent the cutting member, wherein upon insertion of the first end in through an opening of the mantle, the guide acts to constrain the movement of the cutting member such that it is directed along a junction between the internal membrane and an inner surface of the mantle, to thereby detach the internal membrane therefrom, wherein the mantle is inhibited from being perforated by the cutting member.