Evangeline, A Tale of Acadie, is an epic poem by the American poet Henry Wadsworth Longfellow, published in 1847. The poem follows an Acadian girl named Evangeline and her search for her lost love Gabriel, set during the time of the Expulsion of the Acadians.

The idea for the poem came from Longfellow's friend, Nathaniel Hawthorne. Longfellow used dactylic hexameter, imitated from Greek and Latin classics, though the choice was criticized. It was published in 1847 and became Longfellow's most famous work in his lifetime. It remains one of his most popular and enduring works.

The poem had a powerful effect in defining both Acadian history and identity in the nineteenth and twentieth century. More recent scholarship has revealed the historical errors in the poem and the complexity of the Expulsion and those involved, which the poem ignores.

Evangeline describes the betrothal of a fictional Acadian girl named Evangeline Bellefontaine to her beloved, Gabriel Lajeunesse, and their separation as the British deport the Acadians from Acadie in the Great Upheaval. The poem then follows Evangeline across the landscapes of America as she spends years in a search for him, at some times being near to Gabriel without realizing he was near. Finally she settles in Philadelphia and, as an old woman, works as a Sister of Mercy among the poor. While tending the dying during an epidemic she finds Gabriel among the sick, and he dies in her arms.

Longfellow was introduced to the true story of the Acadians in Nova Scotia by his friend Nathaniel Hawthorne. Hawthorne and Longfellow had attended Bowdoin College together, though they were not friends at the time. Years later, in 1837, Hawthorne contacted Longfellow for his opinion on his recently published tales in the North American Review, which Longfellow praised as works of genius; the two became lifelong friends. Hawthorne was not interested in fictionalizing it so Longfellow turned it into a poem after months of studying the histories of Nova Scotian families.

Longfellow, who had never visited the setting of the true story, relied heavily on Thomas Chandler Haliburton's An Historical and Statistical Account of Nova Scotia and other books for further background information. Evangeline was published in book form on November 1, 1847, and by 1857 it had sold nearly 36,000 copies. During this time, Longfellow's literary payment was at its peak; for Evangeline, he received "a net of twenty-five and sixteenths per cent" royalties, believed to be an all-time high for a poet.

Longfellow said of his poem: "I had the fever a long time burning in my own brain before I let my hero take it. 'Evangeline' is so easy for you to read, because it was so hard for me to write".