The sialic acid-binding immunoglobulin-like lectin (Siglec) family comprises a group of immunoregulatory receptors broadly expressed on the surface of immune cells. Their aberrant expression is closely linked to tumor immune evasion, systemic inflammatory responses, and the pathogenesis of autoimmune diseases. Currently, Siglec receptors have attracted extensive attention as potential molecular targets for tumors and inflammatory disorders. In the field of diagnosis, radiopharmaceutical probes targeted Siglec receptors have been developed and applied in molecular imaging such as positron emission computed tomography (PET) and single-photon emission computed tomography (SPECT). In the field of therapy, Siglec-targeted probes labeled with α nuclides (such as 22?Ac and 211At) or β nuclides (such as 1??Lu) enable precise ablation of the focal lesion through targeted radiotherapy, showing advantages particularly in the treatment of hematological malignancies. This article summarizes recent research progress in Siglec-targeted radiopharmaceuticals and analyzes their performance and clinical application value, aiming to provide insights for the development and clinical application of novel Siglec-targeted molecular probes.