The Harold & Kumar actor has welcomed a baby girl with wife Kerri Higuchi, his representative told E! News.
The couple are already parents to a 4-year-old son. They married in 2006.
His reps are yet to reveal any more information about their new child's birth.
John Cho reprises his role as Sulu in the upcoming Star Trek Into Darkness, while he is currently appearing in the comedy Identity Thief.
He is also starring as a series regular in Matthew Perry's NBC sitcom Go On.
Star Trek Into Darkness will open on 3D IMAX screens two days before its May 17 wide release.
Watch a trailer for Star Trek Into Darkness below: