The `One Day` actress` boyfriend of three years, Adam Shulman, recently popped the question with a Kwiat Heritage engagement ring, her rep confirmed to US Weekly.
The couple started dating in 2008 following Anne`s split from Raffaello Follieri, after he pled guilty to 14 counts of money laundering, conspiracy and wire fraud and Anne recently revealed Adam "ruined" her plan of staying single.
She explained: "We hit if off immediately but it took us a pretty long time to get together. He thought that I had a boyfriend and I thought that he had a girlfriend, so I thought that I`d better keep my distance because I didn`t want to be that girl.
"Mellow doesn`t always make for a good story, but it makes for a good life.
"I am very much in love with him, [only] Adam totally ruined my plan. I was really actually looking forward to a little alone time, and then I fell in love like a fool!"
Anne - who had previously been against the idea of getting married - revealed she changed her mind about the institution after witnessing her best friend walk down the aisle.
She said: "I am open to marriage, actually. I just went through a phase where I wanted to look at it from every angle to make sure that I wasn`t just falling in step with some kind of prescribed fantasy.
"I was at my best friend`s wedding recently, and I watched this person who I love like a sister, and who has changed my life and continues to change my life for the better, who I feel as close to as I do my family, commit herself to a man who she loves, and I watched how happy it made her.
"I mean, she looked like she was riding a bubble the whole night. I thought, `Weddings are important because they celebrate life and possibility.` "