Femtosecond degenerate four-wave mixing (DFWM) was used to study third-order nonlinear optical properties of electropolymerized Fe(III) tetrakis(p-hydroxyphenyl)porphyrin films. Third-order nonlinear susceptibility chi(1111)((3)) (-omega;omega,omega,-omega) was determined at 760-1350 nm. Susceptibility chi((3)) values for a 500 nm thick porphyrin film ranged between (2-15)x10(-20) m(2)V(-2) ((1.4-10.7)x10(-12) esu). The time response of electronic nonlinearities was faster than 120 fs. The sum-over-states model was applied to determine real and imaginary components for chi((3)) and molecular second hyperpolarizability, gamma. At wavelengths <800 nm, porphyrin film chi((3)) is enhanced due to the 700 nm one-photon charge-transfer (CT) band. Nonlinear properties at longer wavelengths are determined by a two-photon resonance with a 17400 cm(-1) state. This state was not observed for other porphyrins and is attributed to a two-photon CT transition. Due to the resonance with the two-photon state, porphyrin Im chi((3)) and two-photon absorption cross-section delta increased about 10 times when compared to values in the long-wavelength limit. Because of the contributions of the two-photon state, real component Re chi((3)) had a negative sign in the near-IR spectral range; Re chi((3)) approximate to -6 x 10(-20) m(2)V(-2) at 9000-13000 cm(-1). Results suggest that transition metal CT states can improve third-order nonlinear properties of organic materials.