The Arrow star, 30, posted the photo to Instagram, writing, “I can't wait to spend forever with you my darling!! I'm the luckiest girl in the whole world. I [heart] YOU to the moon and back @mattyice432 Thank you for a magical evening I will forever remember.”
In the shot, Katie flashed her giant oval-shaped diamond engagement ring, while sharing a kiss with her groom-to-be.
Katie and her fiancé, Matt, are currently vacationing at The Oberoi resort on the island of Mauritius off the coast of Africa.
Prior to popping the question, Matt took some pics of Katie in the picturesque location.