杨炎（727年－781年），字公南，凤翔府天兴县人（今陕西省凤翔县），中国唐朝中期的政治家，两税法的创造和推行者。

杨炎风骨峻峙，文藻雄丽，早年即有盛名。通过科举释褐试后，河西节度使吕崇贲聘为书记官，官至中书舍人，后因与宰相元载同乡，受重用为吏部侍郎，大历十二年（777年）元载失势被杀，朝廷派刘晏处理此案，杨炎坐贬道州司马，因此对刘晏有怨恨。唐德宗即位（779年），被宰相崔祐甫推荐，任命为门下侍郎，同中书门下平章事（即宰相），次年建议推行两税法，每年分夏、秋两季征收（称夏输、秋输），全部以钱财征输，废止徭役。两税法使当时受藩镇割据而财用不足的唐朝政府有所助益。

Yang Yan (simplified Chinese:杨炎; traditional Chinese:楊炎; pinyin:Yáng Yán; Wade–Giles:Yang Yen) (727–781), courtesy name Gongnan (公南), was an official of the Chinese dynasty Tang Dynasty, serving as a chancellor early in the reign of Emperor Dezong. He was credited with reforming the tax system to reduce burdens on the peasants and to bring merchants into the rank of taxpayers, but was blamed for using his position to take vengeance on political enemies. He was removed in 781 and soon executed.