Rugowithius bulbosus is a species of pseudoscorpion in the Withiidae family.

The specific epithet bulbosus (Latin: 'swollen') refers to the swollen basal region of the pedipalpal femur.

[1] The species occurs in the Top End of the Northern Territory.

The type locality is Manngarre Rainforest at Cahills Crossing, on the banks of the East Alligator River, Kakadu National Park.

The pseudoscorpions were found under fig tree bark.