Millard Powers Fillmore (April 25, 1828 – November 15, 1889) was one of two children and the only son of US President Millard Fillmore and Abigail Powers. Known familiarly as "Powers", he was born in Aurora, New York. He studied law in his father's office and attended Harvard. He served as his father's private secretary during the latter's presidency. After practicing law in Buffalo, New York, he was appointed a federal court clerk.
After the death of his mother, his father married Caroline Carmichael McIntosh; a union which Millard Powers Fillmore reportedly never accepted. Following his father's death he engaged in a bitter battle with his stepmother over the terms of his father's will, which young Millard won.
Never married and without children, he died in Buffalo of apoplexy. His will directed that all his family correspondence (including that with his father) be burned, the motive for which was the subject of much speculation