Prince Harry has been knighted by his grandmother, the Queen, for "services to the sovereign".
The prince, 30, has been made a Knight Commander of the Royal Victorian Order (KCVO), Buckingham Palace confirmed.
A personal award given by British monarchs for service to them, the honour was given privately at the palace earlier.
The prince is to leave the Army later this month after 10 years of service, including two tours in Afghanistan.
During his military career he has publicly supported charities including Help for Heroes and ABF the Soldiers' Charity.
In March 2014 he launched the Invictus Games for injured members of the armed forces.
He also helped set up the charity Sentebale in Lesotho to help children affected by HIV and Aids.
After leaving the Army, the prince will do voluntary work with a conservation project in Africa and with disabled veterans in the UK.
When his plan to leave the Army was announced in March, he said it had been a "really tough decision" which left him at a "crossroads".
He is said to be considering his options regarding his longer-term plans.
Queen Victoria instituted the Royal Victorian Order in 1896.