节俭悖论（The paradox of thrift or paradox of saving），又名节俭吊诡，是一条经济学上的悖论。早于1714年，它已在《蜜蜂的寓言》（The Fable of the Bees） 一书中提出，但它成为一条普及的悖论、广为人知的经济学假说，则要等到被称为「战后繁荣之父」的英国经济学家凯恩斯在1930年代高举凯恩斯主义旗帜之时。

节俭悖论指出如果社会上每个人试图在经济衰退时期增加储蓄，总需求会下降并会因消费减少导致经济增长放缓，而减少社会上的总储蓄。狭义上而言，此悖论指出当个人储蓄试图增加，总储蓄会下降；或广义上来说，储蓄增加对经济可能有损。不论狭义还是广义，节俭悖论都反映出一个似是而非的「合成谬误」，那就是说「在局部上真实必然在全部上真实」的谬误。

The paradox of thrift (or paradox of saving) is a paradox of economics. The paradox states that if everyone tries to save more money, then aggregate demand and therefore income will fall and will in turn lower total saving (the autonomous portion that changed initially plus the portion induced by the level of income) in the population, because the tendency to save is directly related to the amount of income received. The paradox is, narrowly speaking, that total saving may fall even when individuals attempt to increase their saving, and, broadly speaking, that increase in saving may be harmful to an economy. Both the narrow and broad claims are paradoxical within the assumption underlying the fallacy of composition, namely that what is true of the parts must be true of the whole. The narrow claim transparently contradicts this assumption, and the broad one does so by implication, because while individual thrift is generally averred to be good for the economy, the paradox of thrift holds that collective thrift may be bad for the economy.