The 37-year-old guitarist, who is the son of Ronnie Wood and his late first wife Krissy Findlay, popped the question at the weekend.
Fearne wrote: "I'm over the moon to tell you that on Sunday Jesse proposed and I happened to say Yes."
The news comes after the couple welcomed son Rex Rayne eight months ago.
I'm over the 🌙 to tell you that on Sunday Jesse proposed and I happened to say Yes. ❤️
- fearne cotton (@Fearnecotton) December 12, 2013
The pair started dating in the summer of 2011 after meeting through a friend in a restaurant in Ibiza.
Fearne had not long called off her short engagement to skateboarder Jesse Jenkins when she met Wood, who she calls the love of her life.
Other stars have taken to Twitter to congratulate the Celebrity Juice panellist and Radio DJ, with Leah Wood writing: "@Fearnecotton well we have a COTTONWOOD in the family!! Welcome we are all thrilled!!"
And Jessie J simply wrote: "CONGRATS BABE!"
Now for the most important question: What kind of dress do you think she'll wear?