The British actress and the son of British tycoon Andreas Panayiotou - who have been dating since 2015 - announced their engagement in a sweet post on Instagram, whilst on a romantic getaway in the Southern Province in Zambia, Southern Africa.
Alongside a picture of the pair embracing with a stunning waterfall in the background and Amy's impressive diamond ring on display, the actress - who previously dated soap star Ryan Thomas in 2014 - wrote: "1st January 2019 - The start of our new adventure in life I love you. Thank you for making me the happiest girl in the world (sic)"
Before landing the role of Imra Ardeen in The CW superhero TV series, Amy made a name for herself in Indian films, with her first role in AL Vijay's Tamil film 'Madrasapattinam' in 2010.
She continues to act in films in languages including Tamil, Hindi, Telugu and Kannada.
Prior to launching her acting career, Amy was a model from the age of 16 and won Miss Teen World in 2009.
Amy's boxer ex-boyfriend Joe Selkirk pleaded guilty to assaulting her in 2013.
However, Amy previously admitted it hadn't put her off relationships and only made her stronger.
She said: "It transformed me as a person. It made me not want to rely on anybody. It turned me into a strong and independent woman, who could take care of myself and my mother and people who relied on me. If love comes it's nice but I want none of this crappy attachment. After experiences like that, I didn't want it anymore."
Asked her experiences have made her cautious, she replied: "I still believe in love. I can't wait to fall in love some day. I like the feeling of being in love. I'm a hopeless romantic. But there comes a point where you realise what you deserve and what you want. Love isn't always happy and lovely, it can be painful sometimes. It's nice to be away from love for a while and focus on different emotions and what else one wants in life.