Titanium alloys, characterized by their high specific strength, low density, corrosion resistance, oxidation resistance, high-temperature stability, and low neutron cross-section, are increasingly utilized as critical components in marine and space nuclear power systems. To enhance the radiation resistance of titanium alloys and advance their widespread use in nuclear engineering, considerable efforts have been made by researchers to address key issues related to the irradiation effects on titanium alloys. This paper reviews the development and irradiation effect studies of titanium and its alloys in the nuclear domain, providing a comprehensive overview of defect evolution and interaction mechanisms under various particle irradiations (such as neutrons and ions) across different advanced titanium alloys. Additionally, it summarizes the impact of service conditions (temperature, stress, and irradiation) on the mechanical properties of titanium alloys, including hardness, tensile strength, fatigue, and creep. Finally, based on the current state of research on titanium alloys for nuclear applications, the paper explores future research directions and trends in improving irradiation resistance.