In the present work, iron-functionalized TiO2 nanofibers have been successfully synthesized by an electrospinning system and the resulting nanofibers were characterized using X-ray diffraction, scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectroscopy and ultra-violet-visible spectroscopy. Microscopic studies revealed that TiO2 nanofibers with average diameters of similar to 60 to 65 nm were formed during the electrospinning process while their diameters increased to similar to 85 to 90 nm by iron functionalization. Moreover, the photocatalytic activities of pristine and iron-functionalized TiO2 nanofibers were measured by photodegradation of methyl orange (MO) as a model dye under visible-light irradiation. It was found that iron-functionalized TiO2 nanofibers extended the light absorption spectrum toward the visible region and noticeably improved the photodegradation of MO under visible-light irradiation. Furthermore, there is an optimum amount of FeCl3 to reach to the highest photocatalytic performance of iron-functionalized TiO2 nanofibers under visible-light.