The name of "Hilliard" has been interchanged with the name "Hilliards" for many years until 1960 when it became "Hilliard.” After the Columbus, Piqua and Indiana Railroad was established in the township, the village of Hilliard was laid out in the fall of 1853 by Mr. John R. Hilliard. The village was generally called "Hilliard's Station." The 1888 High School Commencement Program read "Hilliard High School" but the 1895 program read "Hilliards High School." Until 1960 the two names were used interchangeably. The Federal Census of 1960 reflected that Hilliard had a population of 5,633 residents. The Secretary of the State of Ohio issued a proclamation on December 12, 1960.  It read that 30 days thereafter Hilliard would be known as a city in accordance with the Revised Code of the State of Ohio. The "s" was officially dropped from the name and has been "Hilliard" ever since.

Ref: City of Hilliard Proclamation.
Proclamation courtesy of the City of Hilliard.