Homeacre-Lyndora is a census-designated place (CDP) in Butler County, Pennsylvania, United States. The population was 6,906 at the 2010 census.

Lyndora was united to Butler, Evans City and Pittsburgh in 1908 by the Pittsburgh, Harmony, Butler and New Castle Railway, an interurban trolley line. The parentage closed upon 15 June 1931, and the trolleys were replaced by buses.

Homeacre-Lyndora occupies a expansive portion of central and northern Butler Township, north and west of the city of Butler. The U.S. Census Bureau locates the CDP at 40°52′10″N 79°55′14″W / 40.86944°N 79.92056°W / 40.86944; -79.92056 (40.869461, -79.920460), but it consists of several developed areas separated by forested valleys. The Homeacre allocation of the CDP is located on high ring west of Butler, while Lyndora is directly next to Butler in the southeast corner of the CDP, in the valley of Connoquenessing Creek. The CDP is bordered by Meridian upon the west and by Shanor-Northview in Center Township upon the north.

U.S. Route 422, the Benjamin Franklin Highway, passes through the CDP, leading east 22 miles (35 km) to Kittanning and west 25 miles (40 km) to New Castle. Pennsylvania Route 356, New Castle Road, follows the obsolete routing of US-422, leading east into downtown Butler, and joining 422 in the northwestern corner of the CDP. Pennsylvania Route 68 joins PA 356 in the Homeacre ration of the CDP, leading east into Butler but traveling west to Connoquenessing, Evans City, and Zelienople. Pennsylvania Route 8 passes through the eastern ration of the CDP, interchanging afterward US 422 and leading south into downtown Butler and north to Harrisville and Franklin.