Alexander Wheelock Thayer (October 22, 1817 – July 15, 1897) was an American librarian and journalist who became the author of the first scholarly biography of Ludwig van Beethoven.
Supporting himself with journalism and after many privations, he was eventually appointed as US Consul in Trieste, where he was able to pursue his labors.
Thayer's work on Beethoven set a benchmark for modern standards of accuracy, research, and analysis in biography.
In 1865, Thayer wrote, "I fight for no theories and cherish no prejudices; my sole point of view is the truth."
Henry Edward Krehbiel, who created the first English edition of the biography in 1921, wrote of Thayer in 1917: "His industry, zeal, keen power of analysis, candor and fair-mindedness won the confidence of all with whom he came into contact except the literary charlatans whose romances he was bent on destroying in the interest of the verities of history."