"I never told anyone but she knighted me in private," says the text in a picture of a Trump post on Truth Social.
After the death of Queen Elizabeth II, the image was widely spread.
There is a picture of a September 11, 2022, post.
According to CrowdTangle, posts sharing the claim received more than 10,000 interactions. The image and quote were shared by other posts.
The Truth Social post is not in live or archive versions of Trump's Truth Social feed.
"This is not true, Liz," Trump's spokesman said in an email.
In a statement published on Truth Social, the former president expressed his sympathies to the royal family. The queen and Trump were both pictured.
Agence France-Presse found no evidence that Trump posted about a knighthood that the queen gave to a number of US presidents.
There are other pieces of misinformation about Trump's relationship with the queen that have been circulating online.
An image shared widely across Telegram and Facebook appears to show the late monarch wearing a blue sash that says "Trump won" in an attempt to give credence to the false claim that he beat Joe Biden in the 2020 presidential election.
The September 8 Telegram post had more than two hundred thousand views.
The image has been changed The original photo was taken during Trump's visit to Buckingham Palace in London.
There is a Telegram post that was taken in September of 2022.
Britain's Queen Elizabeth II and former US president Donald Trump pose for a photo ahead of a State Banquet in the ballroom at Buckingham Palace.
The queen's death has been fact- checked by Agence France-Presse.