The Avon Hill Historic District is a residential historic district near Porter Square in Cambridge, Massachusetts. It consists of 44 properties, all residential, in a subdivision laid out and developed in the second half of the 19th century around the top of Avon Hill, then also known as Jones Hill. The district includes properties on Washington and Walnut Avenues, and Arlington, Lancaster, Agassiz, and Humboldt Streets in an area southeast of Upland Street and west of Massachusetts Avenue, south of the MBTA station. The houses in the district are one of the city's finest concentrations of late Victorian and Second Empire architecture.