The NHS is "one of our country's greatest treasures", Prince William will say on Monday in a video message to those working in the health service.
In a special recording to be played at an awards ceremony for NHS staff, the prince will say they are the "most wonderful thing" about the service.
He will describe their "skill, care, and dedication" as "inspirational".
The event, honouring staff and the public, coincides with the 70th anniversary of the health service.
The "hero doctor" award will go to Martin Griffiths, a trauma surgeon who saved the life of the first person to be stabbed during the London Bridge terror attack.
By chance, he had also performed life-saving heart surgery on the victim's father several years earlier.
And a sexual health worker credited with uncovering the widespread grooming of underage girls in Rochdale will also receive an award.
Sara Rowbotham's evidence helped lead to the conviction of nine abusers. She is to receive special recognition for her work with vulnerable children.
Manchester attack survivor
The Duchess of Cornwall is expected to attend the event to present a special award, organisers said.
Other guests include Sir Tom Jones, Dame Shirley Bassey, Jamie Oliver and Paul O'Grady, who will host the ceremony.
Elsewhere, the "young fundraising hero" award will go to 15-year-old Freya Lewis – a survivor of the Manchester Arena bombing, who helped raise £40,000 for the Royal Manchester Children's Hospital, where she was treated for serious injuries.
In a video message played to the audience, Prince William will say: "The National Health Service is one of our country's greatest treasures, and something we should all be immensely proud of.
"Perhaps the most wonderful thing about the NHS is its people. The skill, care, and dedication that they provide every day is truly inspirational."
He will also "pay tribute to every member of NHS staff, and the wonderful volunteers who do so much to support them".
"We owe you all a huge thank you."
The NHS Heroes Awards will be broadcast by ITV at 20:30 on 21 May.