Then the rapper turned addressed his support of Mr Trump.
"There's so many times I talk to like a white person about this and they say, 'How could you like Trump? He's racist.' Well, if I was concerned about racism I would've moved out of America a long time ago."
A smattering of applause was quickly drowned out by boos in the audience.
Variety reported that SNL cast members shook their heads during West's unscripted rant and "the entire studio fell dead quiet", according to the Hollywood industry site.
Rock could be heard on the video saying, "Oh, my God."
West was also philosophical during his off-camera monologue.
"You wanna see the sunken place? Okay, I'm-a listen to y'all now," West told the audience, according to Variety.
"I'm-a put my superman cape on, because this means you can't tell me what to do. Follow your heart and stop following your mind. That's how we're controlled.
"You want the world to move forward? Try love."
Earlier, the outspoken rapper, 41, performed his song I Love It dressed as a giant green bottle of Perrier mineral water.
His co-star on the explicit track, rapper Lil Pump, sported a Fiji water costume in an apparent reference to Justin Timberlake famous "Liquorville" sketch.
The sexually-charged song I Love It includes references to water, including the line, "Why you try act like you was drinking sparkling water 'fore you came out here?"
West performed K.T.S.E, a new song with Teyana Taylor, and Ghost Town with Kid Cudi.
He was expected to drop a new album, titled Yandhi, after his appearance on the long-running variety sketch show but it has still not been released.
Meantime, West today announced he would now be known professionally as "Ye".
West previously told a US radio station: "I believe 'ye' is the most commonly used word in the Bible, and in the Bible it means 'you'."
"So I'm you, I'm us, it's us," West said, speaking to Big Boy about the album, Ye.
"It went from Kanye, which means the only one, to just Ye … just being a reflection of our good, our bad, our confused, everything.
"The album is more of a reflection of who we are."
