Over the sitcom's six-years on-the-air the pair formed a friendship that extended far beyond when the director yelled 'cut'.
But as Will went on to navigate the dizzy heights of fame as a blockbuster movie star, and Alfonso - in his own admission 'struggled' to further his acting career - what happened to their friendship?
Here's what the DWTS host has said about Will and their relationship.
What happened to Alfonso Ribeiro after The Fresh Prince of Bel Air?
When the show wrapped in 1996, Alfonso had high hopes that being a star on the show would help further his career.
However, he later confessed that playing Carlton - and becoming famous for his iconic dance - almost derailed his future in acting.
Alfonso was so good as his portrayal of his character that he ended up getting typecast.
"When you do a role like Carlton and people love the role and you do the job so well that they essentially tell you that you can’t do it anymore because we can’t see you as anything else," he told Pop Culture.
"It is a very difficult thing to deal with. It was like, ‘Wait a minute, but I did it well. I did my job. I did what I was asked to do. I made you believe that that’s who I am.’ That’s what any actor is supposed to do."
Did Will help Alfonso to boost his career?
After Alfonso told of his struggles to find work after The Fresh Prince of Bel Air, many criticized Will for not using his fame and fortune to help his friend and his fellow co-stars.
But Alfonso jumped to his defence during an appearance on Sway In The Morning, when he took a different perspective.
"Will Smith has helped me in many ways beyond what we have seen on camera," Alfonso said. "But he has supported me in ways beyond anybody could understand."
Alfonso said he wouldn't read Will's memoirs
Will's self-titled memoir, Will, may have landed on millions of bookshelves around the world, but one of them wasn't Alfonso's.
When asked if he would read his friend's candid work, Alfonso said: "For many, many, many years, people speculated about them as a family. They are laying it out there in a way that is their truth. I don't know if I'll read the book because I know the people."
Is Alfonso Ribeiro still friends with Will Smith?
It is fair to say that their 30-year friendship is still going strong. "[I’ve known] Will… maybe 24, 25 years. Something like that. It’s been a long time," he told Access in 2018.
"We’ve spent many years working together, hanging together, playing together, you know, having families together.
“Will is just a wonderful individual and we have such a great time whenever we're together."
Ahead of the show's 30th-anniversary special, Alfonso addressed fan excitement at seeing the cast back together, when he told Cinema Blend: "At the end of the day, I know everyone always likes to make whenever we get together a big moment. But I look at it very simply as we always get together. We constantly chat. We're family.
"It'll be interesting and fun. I think it's going to be a great special. But for us, it was the same as how we always get together."
Will's most recent social media post is also a tribute to Alfonso as he celebrated his 52nd birthday on September 21.
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