A method for producing a dispersion of iron-containing rutile titanium oxide fine particles, comprising: a step of neutralizing an aqueous metal mineral acid salt solution containing Ti and Fe as metals to form an iron-containing hydrous titanic acid, the masses of the metals in the aqueous solution in terms of oxide being such that mass of Fe 2 O 3 /(total mass of TiO 2 and Fe 2 O 3) = 0.001 to 0.010; a step of adding an aqueous hydrogen peroxide solution to the iron-containing hydrous titanic acid obtained in the step to form an aqueous solution of iron-containing peroxotitanic acid having an average particle size of 15 to 50 nm; a step of adding a tin compound to the aqueous solution of iron-containing peroxotitanic acid obtained in the step in such an amount that the masses of Sn and Ti in the aqueous solution in terms of oxide satisfy mass of TiO 2 /mass of SnO 2 = 6 to 16; a step of adding a sol of silica-based fine particles to the solution obtained in the step, the silica-based fine particles containing Si and at least one metal element selected from the group consisting of Al, Zr, Sb, Zn, Ni, Ba, Mg and V in such amounts that the masses thereof in terms of oxide satisfy mass of SiO 2 /mass of MO x/2 (x is the valence of M) = 99.9/0.1 to 80/20, the addition being made so that the masses in terms of oxide of the metal elements in the solution obtained in the step and the masses in terms of oxide of the silicon and the metal element or elements in the sol satisfy mass of SiO 2 /(total mass of TiO 2, SnO 2, Fe 2 O 3, SiO 2 and MO x/2) = 0.08 to 0.22; and a step of hydrothermally treating the solution obtained in the step to produce a dispersion of iron-containing rutile titanium oxide fine particles. a step of neutralizing an aqueous metal mineral acid salt solution containing Ti and Fe as metals to form an iron-containing hydrous titanic acid, the masses of the metals in the aqueous solution in terms of oxide being such that mass of Fe 2 O 3 /(total mass of TiO 2 and Fe 2 O 3) = 0.001 to 0.010; a step of adding an aqueous hydrogen peroxide solution to the iron-containing hydrous titanic acid obtained in the step to form an aqueous solution of iron-containing peroxotitanic acid having an average particle size of 15 to 50 nm; a step of adding a tin compound to the aqueous solution of iron-containing peroxotitanic acid obtained in the step in such an amount that the masses of Sn and Ti in the aqueous solution in terms of oxide satisfy mass of TiO 2 /mass of SnO 2 = 6 to 16; a step of adding a sol of silica-based fine particles to the solution obtained in the step, the silica-based fine particles containing Si and at least one metal element selected from the group consisting of Al, Zr, Sb, Zn, Ni, Ba, Mg and V in such amounts that the masses thereof in terms of oxide satisfy mass of SiO 2 /mass of MO x/2 (x is the valence of M) = 99.9/0.1 to 80/20, the addition being made so that the masses in terms of oxide of the metal elements in the solution obtained in the step and the masses in terms of oxide of the silicon and the metal element or elements in the sol satisfy mass of SiO 2 /(total mass of TiO 2, SnO 2, Fe 2 O 3, SiO 2 and MO x/2) = 0.08 to 0.22; and a step of hydrothermally treating the solution obtained in the step to produce a dispersion of iron-containing rutile titanium oxide fine particles.