苯海拉明（英语：Diphenhydramine），是一种 第一代抗组胺药，有抗胆碱能、镇咳、止吐和镇静作用，常用来治疗过敏。苯海拉明也用来控制帕金森病和其他锥体外系症状。因苯海拉明有很强的镇静催眠作用，所以FDA批准其作为睡眠辅助药物，尤其是柠檬酸盐形式的苯海拉明。

Diphenhydramine (/ˌdaɪfɛnˈhaɪdrəmiːn/; abbreviated DPH, sometimes DHM) is a first-generation antihistamine possessing anticholinergic, antitussive, antiemetic, and sedative properties that is mainly used to treat allergies. It is also used in the management of drug-induced parkinsonism and other extrapyramidal symptoms. The drug has a strong hypnotic effect and is FDA-approved as a nonprescription sleep aid, especially in the form of diphenhydramine citrate. It is produced and marketed under the trade name Benadryl by McNeil Consumer Healthcare in the U.S., Canada, and South Africa (trade names in other countries include Dimedrol, Daedalon, and Nytol). It is also available as a generic or store brand medication.