The couple were seen kissing and cuddling as they watched the Invictus Games closing ceremony.
A smiling Meghan was seen snuggling up to Prince Harry just days after the couple made their first joint public appearance.
Prince Harry joined Meghan in a private box to watch the ceremony and was seen placing a protective arm around his girlfriend before leaning in for a kiss.
And amid speculation a royal engagement announcement is imminent, the couple were joined by Meghan's mother signalling just how serious the relationship is.
Meghan's mother Doria Ragland flew in from Los Angeles to spend time with the loved–up couple who enjoyed performances by Bruce Springsteen, Bryan Adams and Kelly Clarkson.
The closing ceremony ends the week-long Games, which are aimed at helping the war wounded with their recovery.
Prince Harry addressed the crowd, congratulating the athletes on their successes throughout the seven days.
The Suits actress and her mother were watching the ceremony from a private box at the Air Canada Centre, with Harry joining them after his speech.
Earlier on Saturday, former President Barack Obama joined Prince Harry, along with former vice president Joe Biden and his wife Jill.
Mr Obama is said to have cheekily quizzed the prince about his romance with Meghan Markle during an encounter at the Invictus Games.
The pair, who were sitting side by side at a wheelchair basketball match, were overheard discussing the 36-year-old actress.
Student Hayley Stover, who found herself sitting on the other side of the prince, told the Sunday Mirror: "Obama asked about Meghan and Harry let him know she had been to watch the tennis with him.
"He asked if she was enjoying the Games and Harry was really smiling as he said yes. He looked so happy. It was cute."
The prince and the former President met with the US wheelchair basketball team, all ex-servicemen, before they beat France
Canadian Prime Minister Justin Trudeau’s wife, Sophie Gregoire Trudeau, handed out participation medals to competitors on the arena stage before the start of the ceremony.
At the beginning of the Games, Meghan and Prince Harry were seen laughing and holding hands as they attended the wheelchair tennis in Toronto.
Prince Harry, 33, who set up the Games for injured servicemen and servicewomen in 2014, has told the press his girlfriend is “loving” the Paralympic-style event.
Teams from 17 nations, made up of over 500 participants take part in the annual competition.
During the opening ceremony last weekend, Meghan Markle, 36, sat next to a close friend who is believed to be the man who introduced the pair to one another.
Meghan and Harry have been dating for over a year and one body language expert suggested their relationship progress after the Games.
A body language expert analysed the couple’s body language during the Games and told the Daily Star Online the pair “might be off shopping for rings” ahead of the closing ceremony this evening.
Judi James said: “The royals don't do 'normal'. William and Kate barely if ever touch in public so as an intentional gesture of a possible engagement this has to be an emphatic clue.”
She said Meghan’s appearance at the opening ceremony of the Invictus Games was telling.
Ms James said: “Even the very slightest risk that she might upstage the athletes would normally lead to a royal date being asked to lurk out of sight backstage.
“Instead Meghan was well within snapping distance from her prince which might not sound too romantic or intimate, but in royal terms, it was a very obvious stoking of the fires in terms of press and public speculation.”