Adam Bernard Mickiewicz (24 December 1798 – 26 November 1855) was a Polish poet, dramatist, essayist, publicist, translator, and political activist. He is regarded as a national poet in Poland, Lithuania, and Belarus, and he also largely influenced Ukrainian literature. A principal figure in Polish Romanticism, he is one of Poland's "Three Bards" (Polish: Trzej Wieszcze) and is widely regarded as Poland's greatest poet. He is also considered one of the greatest Slavic and European poets, often dubbed as a "Slavic bard".

He is chiefly known for the poetic drama Dziady (Forefathers' Eve) and the national epic poem Pan Tadeusz. His other influential works include Konrad Wallenrod and Grażyna. All these works served as inspiration for uprisings against the three imperial powers that had partitioned the Polish–Lithuanian Commonwealth out of existence.

Mickiewicz was born in the Russian-partitioned territories of the former Grand Duchy of Lithuania, which had been part of the Polish–Lithuanian Commonwealth. He was active in the struggle to win independence for his home region. After spending five years exiled to central Russia, he succeeded in leaving the Russian Empire in 1829 and, like many of his compatriots, lived the rest of his life abroad. He settled first in Rome and then in Paris, where he lectured on Slavic literature at the Collège de France. A fervent activist, he strived for a democratic and independent Poland.

Mickiewicz died, probably of cholera, in Istanbul, in the Ottoman Empire, where he had gone to help organize Polish forces to fight Russia in the Crimean War. In 1890, his remains were repatriated from Montmorency, Val-d'Oise, in France, to Wawel Cathedral in Kraków, Poland.