Fire crews from Rotherham, Aston and Adwick stations were called to a barge on fire at 11:45pm on Monday night at Main Street in Rotherham.
When firefighters arrived a man and woman were already off the barge which was well alight.
The fire crews used hose reels to tackle the fire.
An investigation into the cause will now take place, however it is believed to be an accidental fire.