贫穷门槛（poverty threshold）或贫穷线、贫困线，是为满足生活标准而需的最低收入水平。一如贫穷的认定，在已发展国家里贫穷门槛（如美国）的认定标准明显比第三世界高。故联合国在1993年把10月17日定为「国际消除贫困日」，联合国秘书长潘基文说全球超过12亿人处于极度贫穷状态，每天靠着不到1.25美元生活，更有24亿人靠不到2美元过活，且从2008年金融危机以来，贫富不均日益显著，他呼吁国际合作消除贫穷，避免社会撕裂与造成不稳定。

如何厘定贫穷门槛时常引起广泛讨论。实际上，不同国家都有不同的贫穷门槛，但普遍来说他们都会利用单一贫穷门槛来比较经济福利程度。在比较国际间的贫穷时常以购买力平价为基准，避免贫穷门槛因兑换率改变。因此「以少于1.25美元生活一天」解释为「一天内购买货物及服务的总开支少于在美国以1.25美元所能购买货物及服务」（自行生产的货物及服务也计算在内）。

The poverty threshold or poverty line is the minimum level of income deemed adequate in a particular country. In practice, like the definition of poverty, the official or common understanding of the poverty line is significantly higher in developed countries than in developing countries. In October 2015, the World Bank updated the international poverty line to US$1.90 a day. Most scholars agree that it better reflects today's reality, particularly new price levels in developing countries. In 2008, the World Bank came out with a figure (revised largely due to inflation) of $1.25 at 2005 purchasing-power parity (PPP). The common international poverty line has in the past been roughly $1 a day. At present the percentage of the global population living under extreme poverty is likely to fall below 10% according to the World Bank projections released in 2015.