Alexander Pollock Moore (November 10, 1867 – February 17, 1930) was an American diplomat, editor and publisher. Born in Pittsburgh on November 10, 1867, he was the publisher/owner of the Pittsburgh Leader when he married the stage actress Lillian Russell, becoming her fourth husband.
After she died on June 6, 1922, he served as an ambassador twice: to Spain from 1923 to 1925 and to Peru from 1928 to 1929. As the Ambassador to Peru he played a significant role in negotiating the Tacna-Arica boundary agreement, settling a border dispute between Peru and Chile. He died on February 17, 1930 in Los Angeles, California shortly after he was appointed Ambassador to Poland by President Hoover.