Provided herein are cyclic polypeptide compounds that can, e.g., bind specifically to human proprotein convertase subtilisin/kexin type 9 (PCSK9) and optionally also inhibit interaction between human PCSK9 and human low density lipoprotein receptor (LDLR), and pharmaceutical compositions comprising one or more of these compounds. Also provided are methods of reducing LDL cholesterol level in a subject in need thereof that include administering to the subject one or more of the cyclic polypeptide compounds or a pharmaceutical composition provided herein.