| January 1 1973 | The United Kingdom, the Republic of Ireland and Denmark enter the European Economic Community, which later becomes the European Union. |
| January 14 1973 | Elvis Presley's concert in Hawaii is watched live by over a billion people worldwide. |
| January 20 1973 | U.S. President Richard Nixon is inaugurated for his second term. |
| January 22 1973 | Lyndon Baines Johnson, 36th President of the United States (b. 1908) dies after suffering his third heart attack. |
| 17th March 1973 | The Queen opens the modern London Bridge. |
| 17th March 1973 | Pink Floyd's “Dark Side of the Moon“ is released and later becomes one of rock’s landmark albums. |
| 4th April 1973 | The World Trade Centre officially opens in New York City with a ribbon-cutting ceremony. |
| 1st May 1973 | An estimated 1,600,000 workers stop work in support of a Trade Union Congress "day of national protest and stoppage" against the Government's anti-inflation policy. |
| 23rd June 1973 | A house fire in Kingston Upon Hull kills a six-year-old boy and is passed off as an accident. It is actually the first of twenty-six fire deaths caused over the next seven years by arsonist Peter Dinsdale. |
| 5th July 1973 | The Isle of Man Post begins to issue its own postage stamps. |
| 20th July 1973 | Bruce Lee, Chinese-American martial artist and actor (b. 1940) dies. |
| 29th July 1973 | Formula One racing driver Roger Williamson dies in an accident, witnessed live on European television, during the 1973 Dutch Grand Prix |
| 15th August 1973 | The U.S. bombing of Cambodia ends, officially halting twelve years of combat activity in Southeast Asia. |
| 20th September 1973 | Billie Jean King defeats Bobby Riggs 6-4, 6-4, 6-3 in a televised tennis match named “The Battle of the Sexes“. |
| 20th October 1973 | The Sydney Opera House is opened by the Queen after fourteen years of construction work. |
| 30th October 1973 | The Bosporus Bridge is completed in Istanbul, Turkey. It connects the continents of Europe and Asia over the Bosporus for the first time in history. |
| 14th November 1973 | Princess Anne marries a commoner, Captain Mark Phillips, in Westminster Abbey. They would eventually divorce in 1992. |
| 31st December 1973 | The Three-Day Week electricity consumption reduction measure comes into force in the United Kingdom, due to coal shortages caused by industrial action. |