Bigneck, also known as Big Neck, is an unincorporated community in Keene Township, Adams County, Illinois, United States. Bigneck is located west-northwest of Golden. The community is served by Illinois Route 61. There remain about two houses in the community and no businesses. Bigneck once had a post office which is now defunct. A. Otis Arnold (1878–1941), Illinois businessman and politician, was born near Bigneck, in Adams County.