Dakota Johnson hailed Taylor Swift the "most powerful person in America" during her 'Saturday Night Live' monologue.

The 34-year-old actress hosted the sketch show for the second time this weekend and as she reflected on her 2015 night at the helm, she couldn't resist poking fun at former US president Donald Trump while praising the 'Anti-Hero' singer.

As a photo appeared on screen of her standing in a star-studded 2015 audience, she said: "The last time I hosted was right after the SNL 40th. I was actually in the audience for that special.

"Look at this photo, look at this collection of people: Sarah Palin, George Lucas, Steven Spielberg.

"And look who's sitting right behind me."

The camera then zoomed in to show the former president, who was also in the audience.

Dakota added: "Crazy to be standing so close to someone who would become the most powerful person in America."

But the camera then zoomed in on Taylor, who was sitting in front of Dakota, prompting the audience to cheer.

Elsewhere in her monologue, Justin Timberlake made a surprise appearance and joked about his own "comeback" ahead of his musical performance later in the show.

She said: "Tonight is also a sort of reunion for me and Justin Timberlake. We were actually in a movie together, called 'The Social Network'."

Justin then appeared on stage, prompting Dakota - who had one scene in 'The Social Network' to ask him: "What are you doing up here, are you lost?"

The 42-year-old singer explained he had heard his voice and thought it was his cue, before offering to help out with any sketches and reminded the 'Madame Web' actress he had hosted before - which she pointed out "was 10 years ago".

She added: "Anyway, I'm so happy you chose my show for your comeback."

Justin replied: "Comeback, is that what we're calling it?"

Dakota reassured him she "meant that in a good way."

The 'Mirrors' hitmaker added: "OK, I see what this is. This is where we make a joke like, 'First he was bringing sexy back, and now he's bringing coming back.' "

Later in the show, the former *NSYNC singer - who has hosted the sketch show five times and was making his sixth appearance as musical guest - performed his new single 'Selfish' and 'Sanctified', the latter of which he was joined by Tobe Nwigwe and a small choir.