Captain Tom Moore said he was “overawed” on finding out he was to be awarded a knighthood for his fundraising efforts.
The war veteran raised more than £32m for NHS charities by walking 100 laps of his garden before his 100th birthday in April.
Captain Tom’s initial reaction was “this can’t be true” when told about the honour.
The centenarian received the special nomination from the prime minister.
Boris Johnson said he had provided the country with “a beacon of light through the fog of coronavirus”.
Capt Tom said he had been “given an outstanding honour by the Queen and the prime minister”.
He added: “I am certainly delighted and overawed by the fact this has happened to me.
“I thought this can’t be true – I’ve always said this won’t happen and it appears it actually has.
“I certainly never anticipated that this letter would arrive for me.”
As an honorary colonel, his official title will be Captain Sir Thomas Moore under Ministry of Defence protocol.
Capt Tom, who was given the honorary title of colonel on his 100th birthday, had initially set out to raise £1,000 for NHS charities by walking laps of the 25m (82ft) loop in his garden in Marston Moretaine, Bedfordshire.
But he eventually raised £32,794,701 from more than one and a half million supporters.
His daughter, Hannah Ingram-Moore, said the knighthood was “simply extraordinary”.
Grandson Benjie Ingram-Moore said: “You never even dream of a letter like this coming through the door.
“It was an amazing moment for him and the entire family.”