衙门，本作牙门，又称官衙，为中国乃至东亚古代对官署的称呼，内有地方官员负责审理案件，衙门中的衙门差役就是协助地方官员搜查证据及逮捕犯人。

衙门本作牙门，这名称至南北朝期间已经出现，按《北史》·卷86·宋世良传：「郡无一囚，每日牙门虚设，无复诉讼者」。

唐代天子处理政务的前殿。《旧唐书》·卷16·穆宗本纪：「群臣始朝于宣政衙。」（820年—824年在位） 唐元稹《连昌宫词》：「蛇出燕巢盘斗栱，菌生香案正当衙。」

清代蒲松龄《聊斋志异》·卷10·胭脂：「鼓动衙开，巍然高坐。」

此外，汉代有衙姓氏，衙谨卿。

A yamen (ya-men; simplified Chinese:衙门; traditional Chinese:衙門; pinyin:yámén; Wade–Giles:ya-men) was the administrative office and/or residence of a local bureaucrat or mandarin in imperial China. A yamen can also be any governmental office or body headed by a mandarin, at any level of government: the offices of one the Six Ministries is a yamen, but so is a prefectural magistracy. The term has been widely used in China for centuries, but appeared in English during the Qing dynasty.