Though Winslet traveled to the billionaire Virgin tycoon's private Caribbean island last month with her on-off boyfriend, model Louis Dowler, 35, she reportedly left smitten with another man, Smith, who was vacationing there with other members of the Branson family, according to Us Weekly.
In fact, Branson credited Winslet with saving his 90-year old mother, Eve, from the fire, which was blamed on a lightning storm caused by Hurricane Irene. The 35-year-old Oscar-winning actress, who was a guest of Branson's at the luxury compound along with her daughter Mia, 10, and son Joe, 7, played the role of hero and carried Branson's mother to safety from the burning building.
"Of course, she was obviously desperate to get her children out and my mother was there so she whisked my mother up in her arms and took her down the steps and anyway, and all is well," Branson said on "Good Morning America."
So well that Smith, 33, reportedly accompanied Winslet back to New York when she left Necker Island. Last week, they were photographed at the London memorial service for Branson's father.
Just who is Ned Abel Smith? Like his uncle, Smith has a few eccentricities. A few years ago he changed his last name to "RocknRoll" after putting the matter out to a vote.
He also has a wife, 23-year-old Eliza Cowdray, the daughter of a wealthy British Viscount. The couple were married in a lavish 2009 ceremony attended by Princess Beatrice, according to the Daily Mail, and they recently separated.
Winslet hasn't been single for very long either. She separated from director Sam Mendes last March and soon began seeing Dowler.
Click through to see more about Winslet's past loves.
In 1991, on the set of the British science fiction series "Dark Season," Winslet met actor and writer Stephen Tredre.
The pair remained close even after their breakup in 1995, and when Tredre died of bone cancer during the opening of "Titanic," Winslet skipped the Los Angeles premiere to attend his funeral in London.
Winslet dated English actor Rufus Sewell for a few months in 1995.
They later starred together in the 2006 romantic comedy "The Holiday," with Jack Black and Cameron Diaz.
Winslet and director Jim Threapleton married in 1998 after meeting on the set of "Hideous Kinky" in 1997.
At their down-to-earth wedding reception they served the traditional English dish bangers and mash, otherwise known as sausage and mashed potatoes.
The marriage lasted three years but produced a daughter, Mia, who was born in October 2000.
Winslet seems to have a thing for directors.
She met Sam Mendes in 2001, and they married in May 2003 and had son Joe in December 2003. They also collaborated on the big screen, when Mendes directed Winslet in "Revolutionary Road" opposite Leonardo DiCaprio. Winslet took home the Golden Globe for her role.
But it was after she won the 2008 Academy Award for "The Reader" that Winslet seemed to have fallen under the best actress Oscar curse. She and Mendes announced their separation in March 2010.
Not long after her separation from Mendes, Winslet began a hush-hush relationship with Burberry model Louis Dowler.
The pair dated for four months in 2010 before parting ways, but reunited again in the summer. Dowler was photographed with Winslet leaving Gatwick airport for Necker Island, but was nowhere to be seen upon their return.