靶向治疗或靶向分子治疗是一种以干扰癌变或肿瘤增生所需的特定分子来阻止癌细胞增长的一种药物疗法，而非一般的干扰所有持续分裂细胞(不稳定细胞)的传统化疗法。放射疗法尽管是针对特定肿瘤的，但是并非此处“靶向”的含义。

癌症靶向治疗在被认为是比当今其他疗法更加有效，并且对正常细胞伤害更小的疗法。

靶向治疗可以治疗乳腺癌，多发性骨髓癌，淋巴癌，前列腺癌，黑色素瘤以及其他一些癌症。

Mark Greene在1985年报告，确切的实验（在体内和体外环境用单克隆抗体处理Her2/neu软化细胞）表明靶向治疗会逆转肿瘤细胞恶性表型。

Targeted therapy or molecularly targeted therapy is one of the major modalities of medical treatment (pharmacotherapy) for cancer, others being hormonal therapy and cytotoxic chemotherapy. As a form of molecular medicine, targeted therapy blocks the growth of cancer cells by interfering with specific targeted molecules needed for carcinogenesis and tumor growth, rather than by simply interfering with all rapidly dividing cells (e.g. with traditional chemotherapy). Because most agents for targeted therapy are biopharmaceuticals, the term biologic therapy is sometimes synonymous with targeted therapy when used in the context of cancer therapy (and thus distinguished from chemotherapy, that is, cytotoxic therapy). However, the modalities can be combined; antibody-drug conjugates combine biologic and cytotoxic mechanisms into one targeted therapy.