印花税，是税的一种，是对合同、凭证、书据、账簿及权利许可证等文档征收的税种。纳税人通过在文档上加贴印花税票，或者盖章来履行纳税义务。

印花税属凭证税，而凭证之种类繁多，并非各种凭证均需贴用印花税票，故税法采枚举式规定，仅规定应税之凭证始应缴纳印花税。而缴纳方式亦非仅贴用印花税票一途，亦可使用缴款书逐件缴纳或汇总缴纳，属于地方税由各县市政府征收。

依照《印花税法》第7条：

印花税是宏观调控的一种手段，现时中国大陆股票交易印花税是0.10%，且为单向征收，应付2007年5月后的股市经济泡沫破裂狂热。

以经济活动中签立的各种合同、产权转移书据、营业帐簿、权利许可证照等应税凭证文档为对象所课征的税。印花税由纳税人按规定应税的比例和定额自行购买并粘贴印花税票，即完成纳税义务。

A stamp act is any legislation that requires a tax to be paid on the transfer of certain documents. Those that pay the tax receive an official stamp on their documents, making them legal documents. The taxes raised under a stamp act are called stamp duty. This system of taxation was first devised in the Netherlands in 1624 after a public competition to find a new form of tax. A variety of products have been covered by stamp acts including playing cards, patent medicines, cheques, mortgages, contracts and newspapers. The items often have to be physically stamped at approved government offices following payment of the duty, although methods involving annual payment of a fixed sum or purchase of adhesive stamps are more practical and common. Stamp acts have been enforced in many countries, including Australia, People's Republic of China, Canada, Ireland, India, Malaysia, Israel, the United Kingdom and the United States of America.