The magnetic tape includes a non-magnetic support; and a magnetic layer including ferromagnetic powder and a binding agent on the non-magnetic support, in which an absolute value ΔN of a difference between a refractive index Nxy measured regarding an in-plane direction of the magnetic layer and a refractive index Nz measured regarding a thickness direction of the magnetic layer is 0.25 to 0.40, and a coefficient of friction measured regarding a base portion of a surface of the magnetic layer is equal to or smaller than 0.30, a magnetic tape cartridge and a magnetic tape apparatus including this magnetic tape.