According to knowledgeable Toronto residents, and architects who have designed buildings in the city, such as Will Alsop and Daniel Libeskind, Toronto has no single, dominant architectural style. Lawrence Richards, a member of the faculty of architecture at the University of Toronto, has said "Toronto is a new, brash, rag tag place a big mix of periods and styles." Toronto buildings vary in design and age with many structures dating back to the mid 19th century, while other prominent buildings were just newly built in the first decade of the 21st century.
Defining the Toronto skyline is the CN Tower. At a height of 553.33 metres it was the world's tallest freestanding structure until 2007 when it was surpassed by the Burj Khalifa, but it is still the tallest tower in the western hemisphere surpassing Chicago's Willis Tower  by 110 metres in height. It is an important telecommunications hub, and a centre of tourism in Toronto.

Toronto is a city of high rises, having over 2,000 buildings over 90 metres (300 ft) in height, second only to New York City in North America. Most of these buildings are residential , whereas the Central business district contains the taller commercial office towers. There has been recent media attention given for the need to retrofit many of these buildings, which were constructed beginning in the 1950s as residential apartment blocks to accommodate a quickly growing population.
In contrast, Toronto has also begun to experience an architectural overhaul within the past five years. The Royal Ontario Museum, the Gardiner Museum, the Art Gallery of Ontario, and the Ontario College of Art & Design are just some of the many public art buildings that have undergone massive renovations.The historic Distillery District, located on the eastern edge of downtown, is North America's largest and best preserved collection of Victorian era industrial architecture. It has been redeveloped into a pedestrian oriented arts, culture and entertainment neighbourhood. Modern glass and steel highrises have begun to transform the majority of the downtown area as the condominium market has exploded and triggered widespread construction throughout the city's centre. Trump International Hotel and Tower, Ritz Carlton Toronto, Four Seasons Hotel and Residences, Shangri La Hotels and Resorts are just some of the many high rise luxury condominium-hotel projects currently under construction in the downtown core.