Abstract: Zinc has become a promising biodegradable metal, following magnesium and iron, owing to its excellent biocompatibility, suitable degradation rate, and strong antibacterial properties. However, the strength of pure Zn is relatively low, and the addition of the nutrient element Fe enhances its mechanical performance. This paper reviews the progress of Zn–Fe-based alloys, focusing on four aspects: microstructure, mechanical properties, degradation behavior, and biocompatibility. The main second phase in Zn–Fe-based alloys is the FeZn₁₃ phase, characterized by a bottom-centered monoclinic structure, which can form 110<−1, 1, −2.81> type I twins, with an orientation difference of about 71° between the twin and parent crystals. During the solidification of Zn–Fe alloy melts, the 110 twining plane serves as the preferred growth interface, causing FeZn₁₃ to feature regular shapes within the Zn matrix. FeZn₁₃ exhibits a hardness of 208 HV, about 4 times that of pure Zn, but has an ultimate compressive strain of just 0.5%, indicating brittleness typical of intermetallics. Adding a small amount of Fe considerably increases the volume fraction of the FeZn₁₃ phase, reaching 50% at 2.6% FeZn₁₃ content. At present, the minimum size of the FeZn₁₃ phase can be refined to about 2 μm using techniques like bottom circulating water-cooled casting (BCWC) and rolling. The crushing effect of rolling on FeZn₁₃ particles is insufficient. It is necessary to combine liquid forming (i.e., BCWC) to refine their sizes to less than 3 μm. Incorporating elements such as Mg, Si, Mn, or rare-earth elements into Zn–Fe alloys can improve strength. For instance, Mn addition leads to the formation of (Fe, Mn)Zn₁₃/MnZn₁₃ core/shell structured second phases. At present, the Zn–Fe based alloy with the highest comprehensive mechanical properties is “BCWC + rolled” Zn–0.3Fe alloy, with a yield strength (YS) of 218 MPa, ultimate tensile strength (UTS) of 264 MPa, and elongation to failure (EL) of 24%. For biodegradable alloys intended for orthopedic implants, the mechanical properties must meet specific thresholds: YS > 230 MPa, UTS > 300 MPa, and EL > 15%. By comparison, the Zn–0.3Fe alloy falls short, with its YS and UTS trailing the requirements of 12 MPa and 36 MPa, respectively. The FeZn₁₃ phase within these alloys has a potential of 317 mV higher than that of Zn, which accelerates the degradation of the Zn phase and causes the formation of corrosion products of Zn(OH)₂, ZnO, Zn₃(PO₄)₂, ZnCl₂, ZnCO₃, and Ca₃(PO₄)₂. Zn–Fe alloys implanted in the body do not form hydrogen and other gases, which is beneficial for tissue repair. Studies also show high cell viability above 85% in Zn–Fe alloy extracts for cells, including human umbilical vein endothelial cells and human osteosarcoma cells. Furthermore, these alloys have hemolysis rates below 5%, indicating excellent blood compatibility. Zn–Fe alloys exhibit nearly 100% antibacterial efficiency against S. aureus. Studies involving rat implantation reveal that these alloys effectively promote the mineralization of osteoid bone tissue into new bone tissue, showcasing excellent osseointegration ability. Future development of Zn–Fe-based alloys should address the challenges posed by low strengthening effects and uneven degradation owing to the coarse FeZn₁₃ phase. Research should focus on understanding property changes during immersion. In addition, conducting long-term studies using large animal models is crucial to advance the clinical application of Zn–Fe alloy implants.