Italian versions of both Vogue and Vanity Fair have said that Pierre and Beatrice will say "I do" on 20 April after Princess Caroline's son recently proposed with a pink diamond ring.
Pierre and Beatrice in France for Prince Félix of Luxembourg and Claire Lademacher's wedding
While there has been no official statement from Monaco's royal family, HELLO!'s sister publication HOLA! reports that experts suggest an announcement could be made after Prince Albert and Princess Charlene's twins are born.
Three months ago Beatrice, 29, spoke to Vanity Fair Italy about her relationship with 27-year-old Pierre.
"I would be happy if Pierre becomes the father of my children," she told the magazine. "I know that it would be great and that together we could create a stable family. But we're not at that point.
"At the moment we are both happy," she added. "[But one day] I would like the responsibility of a family."
The couple at the Monaco Rose Ball
Pierre first set eyes on his Innichen-born love in 2008 while they were both studying at the University Luigi Bocconi in Milan.
Now a journalist and TV presenter who has contributed to publications including Newsweek and The Daily Beast, Beatrice has a bachelor's degree in law and a journalism MA from Columbia University in New York.
For several years Beatrice has been a regular at royal events, such as the Monaco Rose Ball and also attended the wedding of Prince Félix of Luxembourg and Claire Lademacher.
Beatrice has grown close to Pierre's family over the six years they have been together
If the rumours of a wedding are true, they will continue a spell of exciting family news for Monaco's royals.
Since March 2013 both Pierre's brother Andrea and his sister Charlotte have welcomed sons, with Andrea and his wife Tatiana Santo Domingo now expecting their second child.
Princess Charlene is also set to become a mother for the first time when she gives birth to her and Prince Albert's twins any day now.