| 7th January 1990 | The Leaning Tower of Pisa is closed to the public due to safety concerns. |
| 2nd February 1990 | Apartheid: President F.W. de Klerk allows the African National Congress to legally function again in South Africa. He also promises to free Nelson Mandela. |
| 11th February 1990 | James "Buster" Douglas knocks out Mike Tyson to win the World Heavyweight Boxing title. |
| 11th February 1990 | Nelson Mandela is released from Victor Verster Prison, near Cape Town, after twenty-seven years in jail. |
| 9th March 1990 | Police seal off Brixton in South London following protests against poll tax. |
| 15th March 1990 | Mikhail Gorbachev is elected as the first executive president of the Soviet Union. |
| 21st March 1990 | After seventy-five years of South African rule, Namibia becomes independent. |
| 1st April 1990 | The longest prison riot in Britain's history begins at Strangeways Prison in Manchester. It lasts for over three weeks. |
| 2nd May 1990 | In London, a man brandishing a knife robs courier Nicholas Lane of bearer bonds worth £292 million. |
| 1st June 1990 | U.S. President George H. W. Bush and Soviet Union leader Mikhail Gorbachev sign a treaty to end chemical weapon production and begin destroying their respective stocks. |
| 8th July 1990 | West Germany defeats Argentina 1-0 to win the 1990 FIFA World Cup. |
| 2nd August 1990 | Iraq invades Kuwait, eventually leading to the Gulf War. |
| 24th August 1990 | Northern Ireland writer Brian Keenan is released from Lebanon after being held hostage for almost five years. |
| 3rd October 1990 | East Germany and West Germany reunify into a single Germany. |
| 15th October 1990 | Soviet Union leader Mikhail Gorbachev is awarded the Nobel Peace Prize for his efforts to lessen Cold War tensions and reform his nation. |
| 28th November 1990 | Margaret Thatcher resigns as Prime Minister; John Major succeeds her as Party Leader and is appointed Prime Minister by the Queen. |
| 1st December 1990 | Channel Tunnel workers from the United Kingdom and France meet forty metres beneath the English Channel seabed, establishing the first ground connection between the United Kingdom and mainland Europe since the last Ice Age. |