Us magazine reports that Olsen, 25, and her boyfriend, Boyd Holbrook, 32, will tie the knot after dating for two years.

A source close to the couple told Us the pair had been spending a lot of time together, including a recent trip to Paris.

“They moved into a place in Brooklyn a few months ago,” says another source.

Olsen met Holbrook on the set for their movie Very Good Girls in 2012 and instantly hit it off.

"There was great chemistry there," said a source. "She really likes him!"

Just Jared reported Holbrook to be the romantic type, asking Olsen's father for permission before popping the question.

Last week the couple were spotted at the Miu Miu show as part of Paris Fashion Week with Australian actress Margot Robbie.

Olsen's latest screen appearance is in the romantic thriller, In Secret.

This is the second engagement in the Olsen family in two weeks.

Former Full House star Mary-Kate Olsen is engaged to Oliver Sarkozy, the half-brother of former French president Nicolas Sarkozy.

Dating since 2012, Olsen, 27, and Sarkozy, 44, share a $US6 million ($6.7 million) townhouse in New York.

This will be the second marriage for the French banker, who is 17 years Olsen's senior.

Despite the massive bling on her finger, Olsen and Sarkozy haven't officially confirmed their engagement.

When asked about the couple's plans a source told E! News Sarkozy will want a long engagement.

"All we know is that Olivier will want a nice long engagement—he's been through a marriage already and had lovely kids, so he knows what it's all about."

Mary-Kate's twin sister Ashley, 27, is also dating an older man. She is seeing Moneyball director Bennett Miller, 47.

The sisters were last seen promoting the launch of their two new fragrances.

“The fashionista twins attended a Sephora event to celebrate the release of Elizabeth & James' new perfumes, Nirvana Black and Nirvana White,” E! News reports.