Morpholine is an organic chemical compound having the chemical formula O(CH2CH2)2NH. This chemical is a colourless liquid with a fishlike odour used to make other chemicals, as a corrosion inhibitor, and in detergents.

Morpholine is a common additive, in ppm concentrations, for pH adjustment in both fossil fuel and nuclear power plant steam systems and is often used in conjunction with low concentrations of hydrazine or ammonia to provide a comprehensive all-volatile treatment chemistry for corrosion protection for the steam systems of such plants.

Morpholine is also used as a chemical emulsifier in the process of waxing fruit. Naturally, fruits make waxes to protect against insects and fungal contamination, but this can be lost as the fruit is cleaned.