Triethanolamine, also known as tris(2-hydroxyethyl)amine, is an organic compound that can be regarded as a trihydroxy-substituted derivative of triethylamine, with the chemical formula C6H15NO3. Similar to other amine compounds, due to the presence of a lone pair of electrons on the nitrogen atom, triethanolamine exhibits weak alkalinity and can react with inorganic or organic acids to form salts.

The alkalinity of triethanolamine is weaker than that of ammonia (pKa=7.82), and it possesses the properties of both a tertiary amine and an alcohol. It forms salts with organic acids at low temperatures and esters at high temperatures. It forms chelates with various metals, typically with 2-4 ligands. When oxidized with hypochlorous acid, it forms amine oxides. Oxidation with periodic acid decomposes it into ammonia and formaldehyde. Triethanolamine can absorb acidic gases at low temperatures and release them at high temperatures.