Yonge Street ( pronounced `` young '' ) is a main street in Toronto , Ontario , Canada , and its northern suburbs . It was once listed in the Guinness Book of Records as the longest street in the world and is listed as a national historic site . It was formerly listed in the Guinness Book of Records as the longest street in the world at 1896 k , and the construction of Yonge Street is designated an Event of National Historic Significance .