胸苷二磷酸（Thymidine diphosphate，TDP）为一种核苷酸，分子中包含焦磷酸基团、五碳糖，以及碱基胸苷。

Thymidine diphosphate (TDP) or deoxythymidine diphosphate (dTDP) (also thymidine pyrophosphate, dTPP) is a nucleoside diphosphate. It is an ester of pyrophosphoric acid with the nucleoside thymidine. dTDP consists of the pyrophosphate group, the pentose sugar ribose, and the nucleobase thymine. Unlike the other deoxyribonucleotides, thymidine diphosphate does not always contain the "deoxy" prefix in its name.