The present disclosure provides antigen-binding proteins which bind to Claudin-6 (CLDN6). In various aspects, the antigen-binding proteins bind to Extracellular Loop 2 (EL2) of the extracellular domain of CLDN6. Related polypeptides, nucleic acids, vectors, host cells, and conjugates are further provided herein. Kits and pharmaceutical compositions comprising such entities are moreover provided. Also provided are methods of making an antigen-binding protein and methods of treating a subject having cancer.