An extensive analysis of the sensitivity of the fast neutron flux in the superconductor, the dose to the electrical insulator, and the number of displacements per atom in the copper stabilizer to variations of the neutron cross sections for the International Thermonuclear Experimental Reactor (ITER)/OTR inboard region (first wall/blanket/shield/vacuum vessel) was carried out. All of the nuclides with a significant concentration in the ITER/OTR inboard region were investigated, namely, iron, chromium, nickel, lead, oxygen, hydrogen, boron, copper, 6Li, and 7Li. The integrated total sensitivities of iron, lead, hydrogen, and oxygen were compared with the results for the OTR and Next European Torus (NET) sensitivity analyses. The integrated total sensitivity of both the fast neutron flux and the dose to variation of lead cross sections for the ITER/OTR was much higher than that for the OTR, namely, 3.5 and 1.2, respectively. The difference in the integrated total sensitivities of the inboard toroidal field coil responses to a one standard deviation variation of the iron, hydrogen, and oxygen neutron cross sections was <30%. The most important energy regions and the types of neutron cross sections for shield calculations were identified. The uncertainty of the neutron cross sections in the important energy regions needs to be decreased to <10% to decrease the uncertainty of the calculated neutron dose and fast flux behind the ITER/OTR inboard shield to <15 to 30%.