A representative for the couple told the Daily Mail that Jenson and Jessica were "delighted" to confirm that they are set to tie the knot after she was seen sporting a large diamond engagement ring during a trip to Bahrain.
Jessica, 29, who has been dating 34-year-old Jenson for five years, was seen wearing the sparkler as she enjoyed a walk in the Arabian country on Friday.
The Japanese model showed off her teardrop shaped diamond, which is set in a diamond-encrusted silver band, as she sat in the paddock during day three of Formula One Winter Testing.
Jessica and Jenson first met in 2008 in a hotel bar in Tokyo and began dating eight months later.
The couple have maintained a low profile although Jessica is regularly seen supporting F1 star Jenson at his races.
Somerset-born Jenson showed his love for Jessica in 2009, when he dedicated his win to her at the 2011 Formula One Championships in Brazil, on live TV.
Two years later, however, spending so much time apart took its toll on the couple and they briefly split before getting back together six months later.
Shortly after rekindling their romance the sporty duo were seen snuggling up to each other after they both took part in the gruelling Blenheim Triathlon.
Wearing their medals after the event, which involved a 750m swim, 20km bike ride and 5km run, the pair looked very much in love.