He underwent a corrective procedure for the benign condition and could now take up to a month off from public duties as he recuperates.
The monarch smiled and waved to members of the public as he left the private hospital with Camilla, who had visited her husband every day since he was admitted on Friday.
Buckingham Palace said in a statement: “The King was this afternoon discharged from hospital following planned medical treatment and has rescheduled forthcoming public engagements to allow for a period of private recuperation.
“His Majesty would like to thank the medical team and all those involved in supporting his hospital visit, and is grateful for all the kind messages he has received in recent days.”
He left the London Clinic just a few hours after the Princess of Wales was discharged from the same hospital, almost two weeks after undergoing abdominal surgery for an undisclosed reason. Kensington Palace released a statement on Monday to say she is continuing her recovery at home and is “making good progress”.
The family live in Adelaide Cottage in Windsor’s Home Park and are being supported by their staff, including loyal, long-standing nanny Maria Teresa Turrion Borrallo.
The 42-year-old future Queen is not expected to return to official duties until after Easter, and the Prince of Wales has temporarily stepped back from his royal role to juggle caring for her and their children.
A royal source told the Sunday Times the couple has switched to “100 per cent family first, day job second”, however the princess is likely to be working behind the scenes on her early years projects.
Kate’s parents, Carole and Michael Middleton, and siblings, Pippa Matthews and James Middleton, are also expected to be hands-on in helping the family navigate the next few months as the princess recovers.
Among the engagements the princess will miss over the coming weeks are the Baftas in February, the annual Commonwealth Day service in Westminster Abbey, and the St David’s Day Parade at the start of March, as well as the St Patrick’s Day parade with the military later the same month.
It is understood her return to official duties will depend on medical advice nearer the time and that William plans to resume his public engagement once her care and recovery has settled.
Kate will be under the careful watch of royal doctors and also benefit from the London Clinic’s aftercare, with dedicated physiotherapists on hand with a personalised plan and a video check-up at home with a nurse specialist on offer.
It was reported that the King spent time at his daughter-in-law’s bedside before his own treatment.
Charles was diagnosed with the benign condition on 17 January while staying at Birkhall in Scotland, after going for a check-up because he was experiencing symptoms. He is understood to have wanted to share the news to encourage other men to get themselves checked.
NHS England said the “enlarged prostate” page on the NHS website received one visit every five seconds on the day the King’s diagnosis was announced, with further huge boosts in visits in the days that followed.
Buckingham Palace has said the King was “delighted” to learn his diagnosis was having a “positive impact on public health awareness”.
Meanwhile, Downing Street has shared its support for both members of the royal family, saying that the King deserves credit for increasing awareness of prostate issues after sharing news about his own operation.
Asked about Rishi Sunak’s reaction to Charles leaving hospital after treatment for an enlarged prostate, the prime minister’s official spokesperson said: “He’s obviously pleased he’s made a very swift recovery. I understand the NHS website has seen a significant increase in people using it around that issue, and that’s to his credit.”