| 1st February 2003 | At the conclusion of the STS-107 mission, the Space Shuttle ‘Columbia’ disintegrates during landing approach, killing all seven astronauts onboard. |
| 15th February 2003 | More than ten million people protest against the Iraq war in over six hundred cities worldwide. This is the largest protest to have ever taken place before a war. |
| 17th March 2003 | Iraq Disarmament Crisis: U.S. President George W. Bush states Iraqi leader Saddam Hussein and his sons must either leave Iraq within forty-eight hours, or face military action at a time of America's choosing. |
| 19th March 2003 | The first American bombs drop on Baghdad after Iraqi President Saddam Hussein and his sons do not comply with the United States’ ultimatum that had demanding their exit from Iraq. |
| 23rd March 2003 | The 2003 Cricket World Cup ends as Australia beats India by 125 runs in Johannesburg, South Africa. |
| 9th April 2003 | U.S. forces seize control of Baghdad, ending the regime of Saddam Hussein. |
| 22nd July 2003 | Uday and Qusay Hussein, sons of Saddam Hussein, are killed by the U.S. military in Iraq after being tipped off by an informant. |
| 10th August 2003 | The United Kingdom records its highest ever temperature; 38.5°C (101.3°F) at Brogdale near Faversham in Kent. |
| 28th August 2003 | An electricity blackout cuts off power to around 500,000 people living in southeast England and brings sixty percent of London's underground rail network to a halt. |
| 4th September 2003 | Europe's busiest shopping centre, the Bullring in Birmingham, is officially opened by Sir Albert Bore. |
| 12th September 2003 | Johnny Cash, American singer and guitarist (b. 1932) dies. |
| 24th October 2003 | The Concorde makes its last commercial flight, bringing the era of airliner supersonic travel to a close - at least for the time being. |
| 22nd November 2003 | England defeats Australia 20-17 after extra time in the 2003 Rugby World Cup final. The sides are separated by a drop-kick goal that is scored by Jonny Wilkinson with just twenty-six seconds remaining. |
| 24th November 2003 | The High Court in Glasgow imposes a minimum sentence of twenty-seven years for Al Ali Mohmed Al Megrahi, the Libyan convicted of bombing ‘Pan Am Flight 103’ over Lockerbie, Scotland. |
| 1st December 2003 | The use of hand-held mobile phones while driving is made illegal in the United Kingdom. |
| 13th December 2003 | Saddam Hussein, former President of Iraq, is captured in Tikrit by the U.S. 4th Infantry Division. |
| 18th December 2003 | The Soham Murder Trial ends at the Old Bailey in London, with Ian Huntley found guilty of two counts of murder. His girlfriend Maxine Carr is found guilty of perverting the course of justice. |
| 29th December 2003 | Bob Monkhouse, English comedian and game show host (b. 1928) dies. |