Calvin Willard Gilfillan (February 20, 1832 – December 2, 1901) was a Republican member of the U.S. House of Representatives from Pennsylvania.

Calvin W. Gilfillan was born near East Brook, Lawrence County, Pennsylvania.

He attended the common schools and graduated from Westminster College in New Wilmington, Pennsylvania.

He studied law, was admitted to the bar in 1859 and commenced practice in Mercer, Pennsylvania.

He was appointed prosecuting attorney for Venango County, Pennsylvania, in 1861 and elected in 1862 for three years.