Call him Baby Jay.

A 24-year-old Bronx woman gave birth to a healthy baby boy on the J train early this morning.

Transit officials say the woman was riding on the train at 1:32 this morning when the baby was born at Chambers Street. Trains in both directions were halted temporarily while police cleaned the train.

Mom and her new bundle of joy were taken to New York Downtown hospital and are doing fine, transit officials said.

The boy was healthy, said MTA transit chief Joseph Lhota, who joked that the boy should be named “Metro.”

“The boy is healthy and in good condition. He and his mother are in the hospital,” Lhota said. “I’m looking forward to meeting this little baby. I want to have something to do with naming him Metro or somethig like that.”