MILWAUKEE, WI (WSAU) – One of the biggest names in country music will be one of the headliners at one of Wisconsin’s top music festivals next summer. Summerfest 2025 will include ACM and CMA Entertainer of the Year Lainey Wilson as one of its headliners. She will perform on Thursday, June 26 at the American Family Insurance Amphitheater, according to a statement posted on their website.