The former Disney star accepted rocker Chris' proposal last Thursday (8 August) after he popped the question at the top of the Empire State Building in New York.
She later tweeted: "Best night of my life. We're on top of the world".
Now the loved up couple are back in sunny LA, they appear to be inseparable and Ashley couldn't resist flashing her impressive diamond rock on Tuesday afternoon (13 August) while she and her future hubby headed out.
Although Ashley, 28, seemed to be rather coy about letting the cameras catch a glimpse of her ring in New York last week, yesterday she gave them an eyeful.
Walking hand in hand with Chris, the actress could be seen wearing a casual outfit of denim cut-offs and a slouchy grey T-shirt, which she teamed with a pair of black wedge trainers and of course, her most prized and sparkly accessory.
We can see it shining from metres away!
Her musician fiancé looked effortlessly cool too, as he donned a pair of grey jeans, some Converse trainers and a green hoody.
Earlier in the day, Chris had picked up Ashley after she finished a workout. What a gentleman!
The Hollywood star has been inundated with messages from friends, fans and family, congratulating her on the engagement.
Yesterday she tweeted: "Thank you guys for all your well wishes. Means so much to me. We're so grateful and excited. #imthehappiestgirlintheworld"
What do you think of Ashley and Chris as a couple? Let us know below, as the best comment each week wins £50!