United flight 1879 from O'Hare to Los Cabos returned to Chicago shortly after departure due to an "issue with the cockpit windshield," the airline said.
Emergency services met the plane before it taxied to the gate.
"We appreciate the quick action of our crew to keep our passengers and employees safe," United Airlines said in a statement.
Another aircraft was arranged to fly customers to their destination.
The aircraft was a Boeing 737-800 model.
No other information was available.
All passengers deplaned safely. No injuries were reported.