Ethelbert Watts (February 25, 1846 – July 13, 1919) a United States diplomat for over twenty-four years, played important roles in the Spanish–American War, Russo-Japanese War, and World War I.
The second son of United States Minister to Austria Henry Miller Watts and Anna Maria Schoenberger, Ethelbert Watts was born in Philadelphia. He was a great-grandson of Revolutionary War brigadier-general Frederick Watts, and also of lieutenant colonel Henry Miller (1751–1824), who led colonial army units in the siege of Boston and the engagements of Long Island, White Plains, Trenton, Princeton, Brandywine, Germantown and Monmouth. He was the nephew of President Ulysses S. Grant's Commissioner of Agriculture (and the first president of the board of trustees of what is now Penn State University), Frederick Watts.
Ethelbert was educated in Paris, then at the University of Pennsylvania. His junior year at Penn was interrupted in 1863 by Robert E. Lee's invasion of Pennsylvania in the Civil War. He enlisted as private in Company D, Thirty-second Regiment, Pennsylvania Volunteers. Only seventeen years old, his service was limited to the 32nd Regiment Emergency Militia Infantry, which existed from June 26 to August 1, 1863, and performed duties in the Department of the Susquehanna until Lee was driven from the Commonwealth after the Battle of Gettysburg.