Dalam [[fisika teoritisteori]], '''teori medan kuantum''' (bahasa Inggris: ''quantum field therory'' atau '''QFT''') adalah kerangka teoretis untuk membangun model [[mekanika kuantum]] dari [[partikel subatomik]] dalam [[fisika partikel]] dan [[kuasipartikel]] di [[fisika benda terkondensasi]]. It is a set of notions and mathematical tools that combines [[classical field]]s, [[special relativity]], and [[quantum mechanics]]<ref>{{harvnb|Peskin|Scroeder|1995|loc=Preface.}}</ref>, and, when combined with the [[Cluster decomposition theorem|cluster decomposition principle]],<ref>It is related with, but not identical to the notion of [[causality]]. It says in effect, distant experiments yield uncorrelated results.</ref> it may be the ''only'' way to do so,<ref>{{harvnb|Weinberg|1995|loc=Preface.}}</ref> while retaining the ideas of [[Point particle|quantum point particle]]s and [[Principle of locality|locality]]. QFT was historically widely believed to be truly fundamental. It is now believed, primarily due to the continued failures of quantization of [[general relativity]], to be only a very good low-energy approximation, i.e. an [[effective field theory]], to some more fundamental theory.
