The Italian model/actress was photographed sporting the large bauble on her left ring finger while walking in Los Angeles on Tuesday (19Aug14), and made no effort to hide the giant sparkler.
According to E! News, Canalis and her rumoured fiance, spinal surgeon Brian Perri, are planning to tie the knot on 14 September (14) in Sardinia, just two days after her 36th birthday.
Ironically, Clooney is also planning an autumn wedding in September to British lawyer Amal Alamuddin, at his home in Lake Como, Italy.
Canalis split from Clooney in 2011 after 18 months together, and she went on to enjoy an on/off romance with Jackass star Steve-O.