This follows his Vatican visit Thursday with Pope Leo XIV.
The mayor's office shared photos of Thursday's papal visit.
Johnson is traveling with a delegation of nearly four dozen representatives that includes business, community, civic and faith leaders.
Chicago Teachers Union President Stacey Davis Gates; Yusef Jackson, the president and CEO of Rainbow PUSH Coalition; and some unexpected figures like Mary Dillon, the former Foot Locker CEO are part of the delegation.
Talks ranged from the war in Iran to concerns about poverty, immigration and affordability.
Mayor Johnson and his team say they presented the pope with the key to the city and brought a few gifts, including giardiniera and White Sox merch.
Mayor Johnson also extended an invitation for the pope to come back to Chicago and celebrate a Mass in Grant Park next year.
The pope appeared open to the invite.
"We joked a little bit. And then I put on a serious face, and said, 'on behalf of the city of Chicago, and as chair of tourism, it would be an honor to have you officiate a Mass in Grant Park.' And he looked at me, and he said, 'I'd like to do that,'" Choose Chicago CEO Guy Chipparoni said.
Pope John Paul II visited Chicago in October 1979. He said Mass in Grant Park, and roughly a million people came to see him.
Chipparoni speculated Pope Leo would draw five times that.
"It's hard to imagine what kind of impact a visit by the pope would have at his hometown. But that's in the hands of the pope and the Vatican. But the request is in, and up until now there's been no request," Chipparoni said.
Choose Chicago also took out full-page ads in Rome's largest paper, and also plastered bus stops. The ad said, "Our City. His Calling, Elige, or Choose, Chicago."
Boosting tourism is one goal of this trip.
"So we are really looking and talking to leaders of this great country in Italy, just to make certain that we learn from what they are doing. It is, it is actually a challenge for them right now to manage all the tourism, the uptick that they have," Chicago Treasurer Melissa Conyears-Ervin said.
Mayor Johnson toured an affordable housing development and a colosseum train station as part of his visit.
He reflected on a fun moment with the pope when he presented him with a Cubs hat.
"He loves Chicago. So, you know, he comes from that generation of fans where, you know, you have to pick a team. So I don't expect him to wear the Cubs hat, but it's not necessary as long as he just, you know, places some blessed oil on it," Johnson said.
The mayor returns home Saturday.
The trip is funded in part by World Business Chicago, an economic development agency.