The three-match event will showcase teams from the HAC, veterans and military families, the Household Cavalry Regiment and the Parachute Regiment and will raise funds for the HAC Benevolent Fund and the Parachute Regiment Charity.
In addition to the polo tournament, there will be various military attractions, entertainment from the military band, and food and drink stalls.
The lucky winners will spend the day in the VIP tent, managed by Leicester Square nightspot The Pethouse, rubbing shoulders with the celebrity guests.
All you have to do to enter is tell us what film this line comes from: "Avoid the steaming divot".
and leave your answer in the comment box below.