Who is Meghan Markle?

A casually-dressed Prince Harry embraced beaming athletes as he handed out medals at the Invictus games at Toronto's York Lions Stadium.

But there was still no reward for keen royal-watchers, who are eagerly awaiting a glimpse of the Prince with his actress girlfriend Meghan Markle.

The US actress was nowhere to be seen as the competition got under way on Sunday.

Markle was spotted at the opening ceremony in Toronto's Air Canada Centre on Saturday but was seated with a friend and has not yet been seen with Harry at Invictus.

The eight-day Paralympics-style competition for current and former servicemen and women is the Prince's passion project. He founded the games in 2014 to celebrate veterans' service.

Markle's attendance at the games represents an important juncture in the couple's nearly year-long relationship - marking her first outing at one of Harry's official public engagements.

Toronto resident Markle's presence was eagerly documented during the opening ceremony, as she watched on from the stands.

While Harry was seated in an area reserved for VIP spectators during the ceremony, his Suits star girlfriend was around 20 places and four rows away in a public area of the stands, reportedly guarded by the Prince's own protection squad.

While royal-watchers may have been hoping for a more romantic seat pairing, the Prince kept notable company.

He was seated next to US first lady Melania Trump, Canadian prime minister Justin Trudeau and Ukrainian president Petro Poroshenko, whom he had met earlier on Saturday for bilateral talks.

Throughout the games, Harry is expected to attend training sessions and meet the veterans competing in Invictus's 12 sports, which range from cycling to wheelchair basketball.

The games are close to the Prince's heart - he served in Afghanistan and has spoken of being moved by his encounters with wounded servicemen during his first deployment there in 2008.

Kensington Palace has not commented on Markle's appearance at the ceremony.