Provided are a composite for cellulose fiber dispersion that can inexpensively and sufficiently disperse cellulose fibers, particularly nanocellulose, in a hydrophobic resin and a cellulose fiber composition containing the composite. A composite for cellulose fiber dispersion according to the present invention has a structure in which a vinyl polymer is grafted to a cellulose derivative. A cellulose fiber composition according to the present invention contains the composite and cellulose fibers and more specifically also contains an organic solvent, a resin precursor, or a resin.