William Carlile Arnold (July 15, 1851 – March 20, 1906) was an American Republican member of the U.S. House of Representatives from Pennsylvania.

William Carlile Arnold
Member of the U.S. House of Representatives from Pennsylvania's 28th district
In office March 4, 1895 – March 3, 1899
Preceded by	George F. Kribbs
Succeeded by	James K.P. Hall
Personal details
Born	(1851-07-15)July 15, 1851 Luthersburg, Pennsylvania, U.S.
Died	April 20, 1906(1906-04-20) (aged 54) Muskegon, Michigan, U.S.
Political party	Republican

William C. Arnold was born in Luthersburg, Pennsylvania. He attended the public schools and Phillips Academy in Andover, Massachusetts. He studied law, was admitted to the bar in Clearfield County, Pennsylvania, and practiced in Curwensville and Du Bois, Clearfield County, Pennsylvania.

Arnold was elected as a Republican to the Fifty-fourth and Fifty-fifth Congresses. He was an unsuccessful candidate for reelection in 1898. He resumed the practice of law in Clearfield County and died in Muskegon, Michigan, while on a business trip. Interment in Oak Hill Cemetery in Curwensville.