A woman was found dead during a conductor’s midday routine check on board a Queens train over the weekend, cops said. 

The lifeless woman – believed to be between 50 and 60 years old and possibly homeless – was found seated on board a northbound F train at Jamaica-179th Street around 1:45 p.m. Saturday, authorities said. 

A conductor spotted her body during a regular walkthrough at the train’s first stop in the borough, cops said. 

She was pronounced dead at the scene. 

There were no visible signs of trauma. 

The city medical examiner’s office will officially determine her cause of death.