The Ohio man, Jim Walpole, fell on scaffolding on the sidewalk near the front of the King Edward Hotel in Toronto and reportedly began bleeding from his neck.
A doorman at the hotel, Chris Mathias, said in an interview with CTV that the actor, who was smoking a cigarette at the time, stepped over to assist: "Mr. Malkovich was here ... [he] placed his hand and started applying pressure immediately to the man’s neck and didn’t let go until the ambulance arrived."
When reached by phone on Saturday, a guest services manager at the King Edward Hotel confirmed to The Hollywood Reporter that several people, including the doorman, were helping the injured man on the sidewalk.
"I was face down and I don't know whether I turned over or whether the guys turned me over to see where all the blood was coming from. And they just were marvelous," the injured man, Walpole, told CBC News. "They put pressure on the wound and wouldn't let me move until the rescue squad got here."
He was briefly hospitalized after the incident, CBC reported.
Malkovich was in Toronto to portray Casanova in The Giacomo Variations at the Elgin Theatre.
Watch Walpole's interview below: