The Lymantriinae (formerly called the Lymantriidae) are a subfamily of moths of the family Erebidae. The taxon was erected by George Hampson in 1893.

Many of its component species are referred to as "tussock moths" of one sort or another. The caterpillar, or larval, stage of these species often has a distinctive appearance of alternating bristles and haired projections. Many tussock moth caterpillars have urticating hairs (often hidden among longer, softer hairs), which can cause painful reactions if they come into contact with skin.

The subfamily Lymantriinae includes about 350 known genera and over 2,500 known species found in every continent except Antarctica. They are particularly concentrated in sub-Saharan Africa, India, Southeast Asia, and South America. One estimate lists 258 species in Madagascar alone. Apart from oceanic islands, notable places that do not host lymantriines include the Antilles and New Caledonia.