Harry, the fifth in line to the British throne, was seen slipping into Markle's home Wednesday night. Harry, 32, shielded his face with a baseball cap and arrived under the cover of darkness with a duffel bag slung over his shoulder.
Markle, 35, and Harry have been spending time at Harry's cottage at Kensington Palace but Markle had to return to Toronto recently to fulfill her acting commitments on the television show "Suits."
The couple's relationship has seen Harry and Markle jet back and forth across the Atlantic for extended visits. The pair met up in Jamaica in March to attend the wedding of one of Harry's closest friends from Eton.
Markle joined Harry shortly after the wedding at his Nottingham cottage before she returned to Canada at the end of the March.
Markle announced last week that she was shutting down her lifestyle blog, The Tig. Speculation has mounted that the move may be a sign that an engagement for Harry and Markle could be in the cards soon.
Markle, who has been extremely active on social media, would need to scale back her presence online if she were going to join the intensely private royal family.
In a farewell message to her Tig followers, Markle wrote, "You’ve made my days brighter and filled this experience with so much joy. Keep finding those Tig moments of discovery, keep laughing and taking risks, and keep being ‘the change you wish to see in the world.’ Above all, don’t ever forget your worth – as I’ve told you time and time again: you, my sweet friend, you are enough."
While insiders say that Markle intends to focus on her humanitarian work and her acting commitments, the closing of The Tig has still raised eyebrows that an engagement may be imminent.
Princess Kate gave up her job as an accessories buyer before she became engaged in 2010 to Prince William. There are questions about whether Markle will continue her acting career on "Suits" beyond this season or whether she has been asked to be written out of the show so she can spend more time with Harry in London.
The actress has also been increasing her humanitarian profile. In January, Markle made a trip to India on behalf of World Vision and then wrote a powerful essay, released on International Women's Day 2017, on how periods affect young girls who want an education. She has also worked as a United Nations' women's advocate.
Harry's current trip to Toronto will be a quick one. He's due back in London for a series of engagements tied to the Heads Together charity he started with William and Kate last year.
Heads Together released another video last week with Harry encouraging runners ahead of the 2017 Virgin Money London Marathon. William, Kate and Harry are due to attend the marathon on April 23.