Daniel Maurice Casey (November 20, 1862 – February 8, 1943) was a professional baseball player. He was a pitcher over parts of seven seasons (1884–1890) with the Wilmington Quicksteps, Detroit Wolverines, Philadelphia Quakers and Syracuse Stars. He led the National League in earned run average in 1887 while playing for Philadelphia. For his career, he compiled a 96–90 record in 201 appearances, with a 3.18 ERA and 743 strikeouts.
He was born in Binghamton, New York and later died in Washington, D.C. at the age of 80.