In this work, undoped and Fe-doped single-crystalline ZnO nanostructures were successfully synthesized by a facile microwave irradiation method. X-ray diffraction (XRD) and transmission electron microscopy (TEM) results showed that Fe-doped ZnO was comprised of a single phase nature with a hexagonal wurtzite structure up to 5% Fe doping, however, secondary phase ZnFe₂O₄ appeared upon further increasing the Fe dopant concentration. Field emission scanning electron microscopy (FESEM) and TEM micrographs suggested that the length and diameter of the undoped ZnO rods are about ∼2 μm and ∼200 nm, respectively. Interestingly, the morphology of ZnO changed from nanorods (1% Fe) with length ∼500 nm and diameter ∼50 nm to nanosheets (5% Fe) having thickness and lateral dimension of ∼30 nm and ∼400 nm, respectively. NEXAFS and EELS studies revealed the absence of metal clusters up to 5% and Fe is found to be in a mixed (Fe²⁺/Fe³⁺) valence state with Fe²⁺ as the dominant state. Optical studies depicted that the absorption peak of Fe-doped ZnO was blue-shifted as the concentration of Fe increases from 1 to 5%. However, for dopant concentration >5%, the absorption peak was found to be red-shifted with an additional absorption peak of ZnFe₂O₄. Also, the band gap energy decreased monotonically with the increase of Fe concentration from 1 to 5%, while increasing on further doping, band gap increased. Raman scattering spectra of Fe-doped ZnO revealed the lower frequency shift of E^high₂ mode with doping. Magnetic studies showed that Fe doped ZnO exhibit room temperature ferromagnetism (RTFM) and the value of magnetization increased up to 5% doping and then decreased for 7 and 10% Fe-doped samples.