Frank J. Baker House at 507 Lake Avenue in Wilmette, Illinois, is a Prairie School residence designed by Frank Lloyd Wright and completed in 1909. One of Wright’s early suburban houses, it reflects his experimentation with two-story construction and the T-shaped floor plan within the Prairie style. Its strong horizontal lines, low roofline, and deep overhangs express that design approach, while the interior is distinguished by a rare surviving two-story living room centered on a brick fireplace. Added to the National Register of Historic Places on November 8, 1974, the house remains an important example of Wright’s residential architecture and has undergone major restoration since 2020.