David Hayes Agnew (November 24, 1818 – March 22, 1892) was an American surgeon.

Agnew was born on November 24, 1818, Nobleville, Pennsylvania (present-day Christiana).

During the American Civil War he was consulting surgeon in the Mower Army Hospital, near Philadelphia, and acquired a considerable reputation for his operations in cases of gunshot wounds.

On December 21, 1863, he became the Demonstrator of Anatomy and Assistant Lecturer on Clinical Surgery at The University of Pennsylvania.

A large portion of his success was due to his wife's energy, intelligence, and determination.

When a committee came to give him his money for helping, Agnew said, "Gentlemen, I present no bill for my attendance to President Garfield.

[5] David Agnew wrote The Principles and Practice of Surgery, covers an experience of fifty active years, and its value, preserving and presenting as it does the life-work of such a recognized authority, can hardly be overrated.

After a few days his condition began to improve, but suddenly, on March 12 it became much worse.