Helmetta is a borough in Middlesex County, New Jersey, United States. The community was established around a snuff mill opened in the 1820s that was acquired by George Washington Helme in the 1880s. Helmetta was formed as a borough by an act of the New Jersey Legislature on March 20, 1888, when it was created from portions of East Brunswick Township, based on the results of a referendum held on March 10, 1888. Helmetta’s boundary with East Brunswick Township was changed as of March 24, 1897. The borough was named for Helme’s daughter, Olivia Antoinette “Etta” Helme.