The legendary singer invoked the president’s words to the Proud Boys at the first presidential debate, when he told the group to “stand back and stand by”.
Wonder said: “You know what we say in the ghetto when somebody says that, right? Watch yourself, get your ass whupped.”
He urged attendees to maintain social distancing, saying: “We’ve got a situation going on because someone didn’t handle their business right.”
The Michigan native marked Halloween by playing “Superstition” among other hits, including “Overjoyed”.
Referencing an alleged plot to kidnap Ms Whitmer, governor of Michigan, Wonder said: “Excuse my language but that’s some bulls*** — unacceptable.”
Ms Whitmer, who urged rally-goers to turn out in force for Mr Biden on Tuesday, has said Mr Trump’s repeated attacks on her bear some responsibility for the alleged conspiracy and other threats to her life. He has continued to insult her at his events, where his supporters chant “lock her up”.
Wonder echoed the view of people on both sides of the political aisle, saying 3 November’s election was the “most important” of his life.