The 35-year-old, who was previously married to actress Demi Moore, took to photo-sharing website Instagram, to post the picture, reports femalefirst.co.uk.
"Sunset nofilter (sic)," read the caption with the photo.
The couple is said to have started dating in April 2012.
Kutcher's divorce from Moore was finalised last month.
--IANS (Posted on 13-12-2013)