Frederick Leypoldt (born Jakob Friedrich Ferdinand Leupold; 17 November 1835 – 31 March 1884) was a German-American bibliographer, the founder of Library Journal, Publishers Weekly, Index Medicus and other publications.

Frederick Leypoldt was born in 1835 in Stuttgart, Kingdom of Württemberg, his name at birth being Jakob Friedrich Ferdinand Leupold.

[1] Leypoldt had an early liking for the drama and books, and he wrote a play as a youth, which he offered unsuccessfully to German managers.

His Publishers' Uniform Trade-List Annual was begun in 1873, the Literary News in 1875, the Library Journal in 1876, and the Index Medicus, a monthly medical bibliography, in 1880.

Writing of his death, Samuel Swett Green noted, "His friends believed that the zeal that was conspicuous in him led to strenuous labors in furthering his projects of the Publishers' Weekly, the Library Journal and the American Catalogue ...which shortened his life many years perhaps.".