A person is dead after jumping from several stories up at Los Angeles City Hall on Wednesday evening … and TMZ has learned cops are investigating it as an apparent suicide.

Law enforcement tells TMZ … the man jumped just after 4 PM from the Spring Street side of City Hall — and landed onto the front steps of the iconic Downtown landmark.

The person — who it’s believed jumped from the 25th floor or 26th floor — was pronounced dead at the scene. We’re told the person was NOT a city employee.