The portrait, taken by royal photographer for Getty, Chris Jackson, shows Charles and Camilla on a beach in Apia, Samoa.
The Queen, 77, looks elegant in a white tunic dress with blue embroidery, while her husband, dressed in a beige suit, smiles at her adoringly.
Their personal social media message read: "As our visits to Australia and Samoa come to a close, my wife and I would like to thank both nations for the warmest of welcomes and for the countless fond memories we will carry in our hearts for many years to come.
"Even when we are far apart in distance, the many close connections that unite us across the globe and through our Commonwealth family have been renewed, and will remain as profound as they are enduring."
Royal fans flocked to the comments to compliment the portrait and marvel at the success of the overseas trip.
"What a beautiful photo, look how he looks at his Queen," one wrote.
"What a beautiful photograph of our King & Queen! I feel very proud that they are such amazing ambassadors of our country! God save the King & Queen!!" another agreed, while a third said: "Gorgeous photograph showing the deep love, happiness and kindness each have for each other. The King's words are a mirror into his soul, long live our King and Queen."
A fourth commented: "The tour was a huge success! It was beautiful to see the warm welcome everywhere you two went and what a lovely picture."
A palace official revealed that the King "genuinely loved" the tour and "genuinely thrived" on the Australian and Samoan programme, adding that the trip lifted “his spirits, his mood and his recovery.
"In that sense, the tour, despite its demands, has been the perfect tonic".
He went on to say the monarch took great strength from the Queen being there, not least because she "keeps it real".
It's understood that the King will fly abroad during the spring and autumn, the traditional periods for official foreign royal trips, provided doctors sanction the travel.
The monarch has been receiving treatment as an out-patient for an undisclosed form of cancer since early February, and initially postponed all public-facing duties, continuing to work behind the scenes, and returned to events with the public in late April.
Highlights Down Under included the royal couple joining a community barbecue and greeting thousands of people outside Sydney Opera House, while in Samoa, they were given a warm welcome at various tea ceremonies.
LISTEN: Inside King Charles and Queen Camilla's historic royal tour
ROYAL FAN? JOIN THE CLUB
Welcome to The HELLO! Royal Club , where thousands of royal fans like you get to delve deeper into the wonderful world of royalty every day. Want to join them? Just click the button below for a list of club benefits and joining information.
blah blah blah. Shoveling more palace propaganda pr. How bout you go into your deep billion $$ pocket and REALLY HELP some of the struggling people in the UK ? THEN i will believe you and have kind and good feelings toward you. And until then , this is just more hot air and you are a fraud.
Get updates delivered to you daily. Free and customizable.
It’s essential to note our commitment to transparency:
Our Terms of Use acknowledge that our services may not always be error-free, and our Community Standards emphasize our discretion in enforcing policies. As a platform hosting over 100,000 pieces of content published daily, we cannot pre-vet content, but we strive to foster a dynamic environment for free expression and robust discourse through safety guardrails of human and AI moderation.