The Prince and former US president are firm friends, appearing in public together several times over the years.
In a testament to their friendship, the Prince was allegedly overheard speaking about his girlfriend Ms Markle to Mr Obama, who finally attended an Invictus event after being disappointed to miss out in Orlando last year .
Britain’s Prince Harry and former U.S. President Obama Hayley Stover, an 18-year-old carpentry student who sat next to the Prince, said afterwards: I did hear Obama ask about Meghan and Harry just let him know she had been to watch the tennis with him.
Harry was really smiling when he said it. He looked really happy, it was cute. Obama asked how she was just after half way into the game.
Obama just asked about her filming [Suits] and how it was going, and then Harry asked about Michelle and how she was doing. Then Harry said, send my love to Michelle.
Former U.S. President Barack Obama greets competitors from Team France on day 7 of the Invictus Games 2017 on September 29, 2017 in Toronto, Canada
The Prince and Mr Obama caused something of a stir at the wheelchair basketball, with former president chanting USA, USA as they made their way to watch the US vs France game.
A spokesman for Mr Obama said the former president wished to lend his support to American competitors to once again express his gratitude for their service and his admiration for their courage and resilience.
It was a hero’s return for Mr Obama to the Invictus Games, after he helped raise its profile in an extraordinary video series last year.
Then, he and his wife Michelle issued a video message challenging Prince Harry’s British competitors to bring it at the Florida Games.
Britain’s Prince Harry and his girlfriend actress Meghan Markle Enlisting the help of his grandmother, the Prince responded in kind, with the Queen delivering a comically withering oh really? in a film which was seen around the world.
In May this year, the Prince and Mr Obama met at the Prince’s home, Kensington Palace, while the former president was visiting the UK, discussing among other things mental health and the Manchester bombing which had happened days before.
They also spent time together in 2016, when Mr and Mrs Obama joined the Duke and Duchess of Cambridge and Prince Harry for dinner during an official visit.
This year, he dropped into the Toronto Games on its second-to-last day, in a casual appearance at the wheelchair basketball.
Meghan Markle and Prince Harry seen chatting at the Closing Ceremony on day 8 of the Invictus Games on Sept. 30, 2017, in Canada.
Barack Obama and Prince Harry watch wheelchair basketball at the Pan Am Sports Centre at the 2017 Invictus Games in Toronto, CanadaCredit: Danny Lawson
It was a marked constant to Prince Harry’s official meeting with Melania Trump, the current US First Lady, in a formal photocall and private unilateral meeting behind closed doors.
The Prince will attend several more sporting events before delivering an address at the closing ceremony on Saturday night.
Joe Biden, former VP and his wife Jill also attended that game.
Among those who met the Prince and Mr Obama were three small children who approached the pair shyly for a photograph.
Prince Harry and former U.S. President Barack Obama converse as they watch a wheelchair basketball event with former Joe and Jill Biden at the Invictus Games in TorontoCredit: Reuters
Otis Harding-Withers, six, was lifted onto Prince Harry’s lap after saying hello, while Jakob Israel, eight, and his seven-year-old sister Grace posed in front of Mr Obama.
Jakob and Grace are the children of Jason Israel, who has served three tours in Afghanistan with the Canadian forces and and competed in the track events after suffering an operational stress injury.
Their emotional mother Amanda Israel, said she had used the moment to thank Prince Harry for setting up the Games.
I told him: thank you for giving me my husband back, she said. It was the first time we could share and say thank you to him.
The fact Barack Obama was with him as well, incredible.
Grace has been talking about him all week.
Heather Harding, mother of Otis, said her son has simply walked over towards the Prince just as he and Mr Obama settled into their front row bleacher seats.
Harry asked me if it was ok and put him on his lap,” she said. “He was as lovely as I thought he would be.