Philly forever! Will Smith gave Ellen DeGeneres' studio audience a thrill when he whipped out his famous Fresh Prince of Bel-Air theme song for an amazing sing-along. The ‘90s star had stopped by the daytime talk show to promote his upcoming film Focus.

"This is how you know if you got real fans in the house!" Smith, 46, said, before busting out the tune.

Clad in leather pants, he also rolled up his sleeves and shook his hips for the crowd. At one point, he let the audience do the singing for him.

"They gotta give me an instrumental or something," he said, joking. The star also sang his 1991 hit "Summertime."

The Fresh Prince of Bel-Air ran from 1990 to 1996. Back in May 2013, Smith returned to the Banks days once again when he, Alfonso Ribeiro (Carlton Banks), and DJ Jazzy Jeff sang the theme song on Britain's The Graham Norton Show. Ribeiro also did the "Carlton Dance," and the trio — plus Smith's son Jaden — danced to Sugarhill Gang’s "Jump On It."

Watch the videos above!