James Lusk Alcorn (born November 4, 1816) was a Republican senator from Mississippi who served one term in the United States Senate during the Reconstruction era. Representing the state of Mississippi, he held office from March 4, 1871, to March 3, 1877. During this period, he was affiliated with the Republican Party, which, in the post–Civil War years, was the principal national party associated with Reconstruction policies in the South.

Alcorn’s tenure in the Senate marked his role as a historical member of Congress from Mississippi in the years immediately following the Civil War. Serving as a senator for a single term, from 1871 to 1877, he participated in national legislative life at a time when Mississippi was being reintegrated into the Union and its political institutions were being reshaped. His service as a former senator from Mississippi remains the central recorded element of his public career in the available metadata.