杜兰线（Durand Line，普什图语：د ډیورنډ کرښه‎、乌尔都语：ڈیورنڈ لائن‎）指巴基斯坦和阿富汗长达2640公里的边界分界线。

英国征服阿富汗的二次战争，结果双方僵持不下，1893年11月12日英国外交大臣莫蒂默·杜兰作为英国女王全权代表与阿富汗国王阿布杜尔·拉赫曼·汗在喀布尔订约划定。英国人以此作为阿富汗和英属印度的分界线；该分界线以当时的英属印度政府外交大臣莫蒂默·杜兰主持起草，以其名字命名。

由于杜兰线是英国入侵阿富汗时强加给阿富汗当局的，从当时的阿富汗国王开始到现在，一直存在争议。当时英国人划分此线，目的是拆散使其畏惧的普什图族，至今，普什图人一半生活在巴基斯坦控制的边界一侧，另一半在阿富汗边界一侧。

The Durand Line (Pashto:د ډیورنډ کرښه‎) is the 2,250-kilometre (1,400 mi) long line between Afghanistan and Pakistan. It was established in 1893 between Sir Mortimer Durand, a British diplomat and civil servant of British India, and Abdur Rahman Khan, the Afghan Amir, to fix the limit of their respective spheres of influence and improve diplomatic relations and trade. Afghanistan ceded various frontier areas to British India to prevent invasion of further areas of the country. Afghanistan was considered by the British as an independent princely state at the time, although the British controlled its foreign affairs and diplomatic relations.