The second-year pass catcher took to the streets of Pittsburgh wearing his full uniform as he collected candy alongside local children.
"Happy Halloween," Smith-Schuster wrote on social media. "I got best costume for sure!"
Smith-Schuster put on a Michael Myers mask for some of his exploits. He also walked up to cars giving out treats and saying "free candy."
One driver asked if it was actually JuJu, prompting the wide receiver to remove his mask and reveal his identity.
"That's awesome," the driver said.
Smith-Schuster, 21, has 594 yards and two touchdowns on 46 receptions this season. The USC product had 917 yards and seven scores on 58 receptions in 14 games during his rookie campaign.
Some of Smith-Schuster's Steelers teammates also participated in the holiday. Ramon Foster and his family dressed up as characters from Harry Potter, with Foster going as Hagrid. Cam Heyward and his family dressed up as characters from the Avengers.
The Steelers have an AFC North clash against the Ravens at 1 p.m. on Sunday at M&T Bank Stadium in Baltimore.