Police arrested Carlos Hegge, 47, after they responded to a call at a home on Magoffin Avenue around 1AM.
A third party in the home called police after they said they witnessed Hegge throw boiling water on his girlfriend.
Police say the woman was taken to UK hospital with serious burns to her stomach, thighs and hands.
She is reportedly in stable condition.
Hegge faces 2nd degree domestic violence assault charges.