| Year | Date | Events | 
|---|
| 1900 | January 24 | The Evening Star is renamed as  The Toronto Daily Star. [15] | 
|  | The Art Museum of Toronto opens. [16] | 
| 1903 | May 11 | King Edward Hotel opens. [17] | 
| 1904 | April 19 | The second Great Fire of Toronto occurs. | 
| December 12 | First escalator in Toronto is installed at an Eaton's store on Queen Street West. | 
| 1905 | December 2 | The first Toronto Santa Claus Parade is held. | 
| 1906 | November 19 | Electricity generated at Niagara Falls begins to be supplied to Toronto. [18] | 
|  | The Toronto Professional Hockey Club is established as the first professional ice hockey team in Toronto. [19] | 
| 1909 | September 1 | A fire damages the west wing of the Ontario Legislative Building, destroying the Legislative Library. [20] | 
| October 28 | The Central Reference Library opens at the intersection of College Street and St. George Street. | 
| December 4 | The first Grey Cup game is held at Rosedale Field. | 
| 1911 |  | The Toronto Blueshirts are established. | 
| 1912 | October 7 | The Arena Gardens (later known as Mutual Street Arena) opens as the largest auditorium in Canada with the first artificial ice rink in Ontario. | 
|  | Toronto Civic Railways is established. | 
| 1913 | June 13 | The Toronto General Hospital relocates to its present site at College Street. | 
| 1914 | March 11 | The Toronto Blueshirts win the first Stanley Cup by a Toronto team. | 
| March 19 | The Royal Ontario Museum opens. | 
|  | "Ranelagh Park" estate home, later to be the Guild Inn opens. | 
| 1915 | November 15 | Chorley Park, Ontario's fourth and last Government House, opens. | 
| 1916 | September 16 | The  Ontario Temperance Act  takes effect. | 
| 1917 |  | The Toronto Blueshirts are renamed as the Torontos. | 
| 1918 | March 30 | The Torontos are renamed as the Toronto Arenas. | 
| October 18 | The Prince Edward Viaduct officially opens. [21] | 
| 1919 | December 8 | A statue of Timothy Eaton is unveiled on Queen Street West. [22] | 
|  | The Art Museum of Toronto is renamed as Art Gallery of Toronto. [23] | 
|  | The Toronto Arenas are renamed as the Toronto St. Patricks. | 
| 1920 | August 28 | The Pantages Theatre opens as Canada's largest theatre. | 
| 1921 | September 1 | The Toronto Transportation Commission is established. | 
| December 16 | The Coliseum opens on the Exhibition grounds. | 
| 1922 | June 13 | North York is incorporated as a township. | 
| June 28 | Sunnyside Amusement Park opens. | 
| November 22 | The first Royal Agricultural Winter Fair opens. | 
| 1923 | February 8 | First radio broadcast of an ice hockey game is made from Arena Gardens. | 
| 1924 | January 1 | East York is incorporated as a township. | 
| July 19 | Telephone system begins switch from manual to automatic dialing. | 
| 1925 | June 10 | Arena Gardens hosts a worship service inaugurating The United Church of Canada. | 
| July 29 | Sunnyside Pool opens at Sunnyside Amusement Park as the largest outdoor pool in the world. | 
| August 8 | First automatic traffic signal begins operation at the intersection of Yonge Street and Bloor Street. | 
| 1926 | April 29 | Maple Leaf Stadium opens as the Fleet Street Baseball Stadium. | 
| 1927 | February 14 | The Toronto St. Patricks renamed as the Toronto Maple Leafs. | 
| June 1 | First liquor stores in Toronto open following repeal of the Ontario Temperance Act. | 
| August 6 | The new (present-day) Union Station is open. | 
| August 30 | Edward, Prince of Wales and Prince George inaugurate the new Princes' Gates at the Exhibition Grounds | 
| 1928 | November 3 | First sound film in Toronto is shown at the Uptown Theatre. | 
| 1929 | June 11 | The Fairmont Royal York is opened as the Royal York Hotel. | 
| October 29 | The Toronto Stock Exchange suffers its worst loss in history. | 
| 1930 | January 21 | Cross Waterfront Railway Viaduct opens to elevate tracks from York Street to Queen Street West. | 
| 1931 | January 31 | Commerce Court North opens as the tallest building in the British Commonwealth. | 
| June 4 | The intersection of College Street-Carlton Street and Yonge Street opened. | 
| November 12 | Maple Leaf Gardens opens with hockey game between the Toronto Maple Leafs and Chicago Black Hawks. | 
| 1933 | July 11 | Anti-fascism march, from Bathurst and Wellington Streets, to Queen's Park. [24] | 
| August 16 | Christie Pits riot occurs. [25] | 
| 1934 |  | Fort York Guard created. | 
| March 6 | Centennial of the City of Toronto | 
| 1936 |  | The Globe  and  The Mail and Empire  merge to create  The Globe and Mail . | 
| 1938 | August 29 | Malton Airport opens. | 
| 1939 | February 4 | Toronto Island airport opens. | 
| May 22 | King George VI and Queen Elizabeth The Queen Mother visit, marking the first visit of a reigning monarch to Toronto. The island airport is renamed Port George VI Island Airport in honour of the visit | 
| June 7 | Queen Elizabeth Way (QEW) between Toronto and Niagara Falls, Ontario is opened. | 
| 1944 | December 12 | The Great Snowstorm, the worst winter storm in Toronto's history, ends with nine deaths and 57 cm of snow. [26] | 
| 1947 | April 3 | The Silver Rail opens as the first bar licensed by the LCBO . [27] | 
| 1949 | January 18 | Conversion of hydro in Ontario to 60 cycles from 25 cycles begins. | 
| September 17 | SS Noronic burns at the Toronto Harbour resulting in 118 fatalities. | 
| 1951 | August 9 | Canada Life Building's weather beacon begins operation. | 
| October 11 | The future Queen, Princess Elizabeth and husband Prince Philip visit Toronto as part of a cross-Canada tour. [28] | 
| December 1 | The Toronto-Barrie Highway opens. | 
| 1952 | July 1 | The Toronto-Barrie Highway is renamed as Highway 400 | 
| September 8 | Ontario's first television station, CBLT, begins broadcasting in Toronto. | 
| November 1 | First English broadcast of  Hockey Night in Canada  is televised from Maple Leaf Gardens. | 
| 1953 | January 20 | The Metropolitan Toronto School Board, a school board with a federation of 11 school boards, is formed. | 
| 1954 | January 1 | Metropolitan Toronto is created. | 
| March 30 | The Yonge subway line opens as the first rapid transit line in Canada. | 
| September 9 | Marilyn Bell becomes the first person to swim across Lake Ontario. | 
| October 15 | Hurricane Hazel affects Toronto and kills a total of 81 people in Ontario. | 
| 1956 | August 24 | Highway 401's last section in Toronto from Bayview Avenue to Highway 2 opens. | 
| 1958 | August 8 | The Gardiner Expressway from Humber River to Jameson Avenue opens. | 
| 1960 | October 1 | The O'Keefe Centre opens. | 
| 1961 | August 3 | The Don Valley Parkway's first phase, from Bloor Street to Eglinton Avenue opens. | 
| 1964 | February 26 | The Yorkdale Shopping Centre opens. | 
| 1965 | September 13 | The Toronto City Hall and Nathan Phillips Square open. | 
| November 10 | Northeast Blackout of 1965 occurs. | 
| 1966 | February 25 | The Bloor-Danforth subway line (Line 2) opens. [29] | 
| October 21 | The Spadina Expressway opens. | 
| 1967 | May 2 | The Toronto Maple Leafs win the Stanley Cup, their most recent win. | 
| May 23 | GO Transit is established. | 
| July 1 | Official opening of 56-storey Toronto-Dominion Bank Tower. | 
|  | Etobicoke, East York, North York, Scarborough, and York are incorporated as boroughs. | 
| 1968 | October 28 | The McLaughlin Planetarium opens. | 
| 1969 | September 26 | The Ontario Science Centre opens. | 
| 1970 | July 5 | The Air Canada Flight 621 accident occurs as the deadliest aviation incident in Toronto. | 
| 1971 | May 22 | Ontario Place opens. | 
| June 3 | The Spadina Expressway project into downtown is cancelled to go no further than Eglinton Avenue. | 
| November 6 | The Toronto Daily Star is renamed as The Toronto Star . | 
| 1972 |  | Toronto's first Gay Pride Week is held. It includes a dance, film night, and march to Queen's Park. [30] | 
| 1973 | May 2 | The Scarborough Town Centre opens. | 
| 1974 | August 15 | Toronto Zoo opens (originally called Metro Toronto Zoo). | 
| October 26 | Art Gallery of Ontario relocates to its present site on Dundas Street. | 
| 1975 | May 18 | The First Canadian Place opens as the tallest building in the Commonwealth of Nations. | 
|  | The 519 Church Street Community Centre is established. [31]  The 519 provides services to LGBTQ2S people. | 
| 1976 | February 11 | The Toronto Eaton Centre opens. | 
| June 26 | The CN Tower opens as the tallest freestanding structure in the world. | 
| August 3 | The opening ceremony of the 1976 Summer Paralympics is held at the Woodbine Racetrack. | 
| November 2 | Toronto Reference Library relocates to its present site at the intersection of Bloor Street and Yonge Street. | 
|  | The first Toronto International Film Festival is held (originally called the Festival of Festivals) | 
| 1979 |  | North York is incorporated as a city. | 
| 1981 | February 5 | Police raid four gay bathhouses in Operation Soap and arrest 286 people. The next day over 3,000 people demonstrate against the raids. Smaller raids and protests continue through 1981. | 
| May 23 | Canada's Wonderland opens. | 
| 1982 | September 13 | The Roy Thomson Hall opens. | 
| 1983 |  | Etobicoke, Scarborough, and York are incorporated as cities. | 
| 1984 | October 2 | The Metro Toronto Convention Centre opens. | 
| 1985 | March 22 | The Scarborough RT line opens. | 
| 1988 | March | Canada's first stand-alone treatment facility for people with HIV/AIDS, Casey House opens its doors. | 
| 1989 | June 5 | Rogers Centre opens (originally known as SkyDome). | 
| 1991 |  | The 1991 Toronto bomb plot is revealed. | 
| 1992 | May 4 | A riot occurs after a protest march after the police shooting of Raymond Lawrence, a young black man. | 
| 1993 | May 23 | The Princess of Wales Theatre opens. | 
| 1995 | August 11 | The Russell Hill subway accident occurs. | 
| 1998 | January 1 | East York, Etobicoke, North York, Scarborough, Old Toronto, York and Metro Toronto are amalgamated into the new City of Toronto. | 
| 1999 | February 19 | The Air Canada Centre opens. |