She looked chic in a black coat over blue jeans and trainers as she sported a pair of gold-rimmed aviator shades.
Ryan made the announcement on Instagram with a sweet sketch accompanied with one word "ENGAGED!"
The When Harry Met Sally. star posted a hand-drawn cartoon of herself holding hands with the U.S. singer-songwriter, simply captioned: "ENGAGED!"
The couple will now bag a total of five marriages between them, for Mellencamp this will be his third marriage and for Ryan it will be her second. "She was just an angel sent to me at the right time", Mellencamp told radio personality Howard Stern at the time.
After saying that the actress "hates him to death", he added: "Oh, women hate me". And I can't blame her'.
It's a great twist of fate for the "When Harry Met Sally" actress and the "Hurts So Good" singer.
'I throw fits, I gripe, I complain. "I'm moody. Every bad thing that a fella can be, that's me". 'It was the long distance that ultimately was the cause'.
Meg was seen out and about this week, sporting what appeared to be an engagement ring. "You know, I love Meg Ryan", Mellencamp declared. In Mellencamp's three ex-wives, while Ryan was married to actor Dennis Quaid, whom she divorced in 2001. The couple share their son Jack, age 26.
The breakdown of her marriage and how she was portrayed in the tabloids forced Ryan to step out of the spotlight, and lead a quiet life away from Hollywood.
Shortly after the interview aired in March, 2017, Meg and John reconciled and were spotted out in New York City.