Tung oil, pale-yellow, pungent drying oil obtained from the seeds of the tung tree.

On long standing or on heating, tung oil polymerizes to a hard，waterproof gel that is highly resistant to acids and alkalies.

It is used in quick-drying varnishes and paints, as a waterproofing agent, and in making linoleum, oilcloth, and insulating compounds.

Tung oil is produced chiefly in China from the tung tree.