Hiram Berdan (September 6, 1824 – March 31, 1893) was an American engineer, inventor, military officer, marksman, and guiding force behind and commanding colonel of the United States Volunteer Sharpshooter Regiments during the American Civil War.

A mechanical engineer in New York City, he had been the top rifle shot in the country for fifteen years prior to the Civil War.

In the summer and fall of 1861, he was involved in the recruiting of eighteen companies, from eight states, which were formed into two sharpshooter regiments with the backing of General Winfield Scott and President Abraham Lincoln.

His men, who had to pass rigorous marksmanship tests, were dressed in distinctive green uniforms and equipped with Sharps breech-loading rifles.

[2] At the Battle of Gettysburg, his two regiments of sharpshooters played an important role in delaying Confederate attacks on Devil's Den and the Peach Orchard.

In a sharp encounter in Pitzer's Woods on Seminary Ridge, the 1st U.S. Sharpshooters stalled the advancing Alabama brigade of Cadmus Wilcox.