Trooping the Colour is a ceremony performed by regiments of the British Army. It has been a tradition of British infantry regiments since the 17th century, although its roots go back much earlier. On the battlefield, a regiment's colours, or flags, were used as rallying points. Consequently, regiments would have their ensigns slowly march with their colours between the ranks to enable soldiers to recognise their regiments' colours.

Since 1748, Trooping the Colour has marked the official birthday of the British sovereign. It is held annually on the second Saturday in June, coinciding with publication of the Birthday Honours List, and usually takes place at Horse Guards Parade by St James's Park, London. Among the audience are the Royal family, invited guests, ticket holders and the general public.

The ceremony is broadcast live by the BBC within the UK and is also shown in Germany, Austria and Belgium and via live streaming on BritBox in both the United States and Canada. In the parade of 2018, Associated Press provided live streaming of the event to viewers across the world on the Time magazine YouTube channel and the Facebook page of the British newspaper The Telegraph. In 2019, the BBC took over the online broadcasts via its Youtube channel, providing a live feed of its television broadcasts for the second ever international broadcast of the event.The Queen travels down the Mall from Buckingham Palace in a royal procession with a sovereign's escort of Household Cavalry (mounted troops or horse guards). After receiving a royal salute, she inspects her troops of the Household Division – both foot guards and horse guards – and the King's Troop, Royal Horse Artillery. Each year, one of the foot-guards regiments is selected to troop its colour through the ranks of guards. Then the entire Household Division assembly conducts a march past the Queen, who is saluted from the saluting base. Parading with its guns, the King's Troop takes precedence as the mounted troops perform a walk-march and trot-past.Music is provided by the massed bands of the foot guards and the mounted Band of the Household Cavalry, together with a Corps of Drums, and occasionally pipers, totalling approximately 400 musicians.Returning to Buckingham Palace, the Queen watches a further march-past from outside the gates. Following a 41-gun salute by the King's Troop in Green Park, she leads the Royal family on to the palace balcony for a Royal Air Force flypast.In 2020 and 2021, a scaled-down ceremony, with no public audience, was held at Windsor Castle, due to the COVID-19 pandemic.