A subshrub (Latin suffrutex) or dwarf shrub is a short shrub, and is a woody plant. Prostrate shrub is a related term. "Subshrub" is often used interchangeably with "bush".

Because the criteria are matters of degree (normally of height) rather than of kind, the definition of a subshrub is not sharply distinguishable from that of a shrub; examples of reasons for describing plants as subshrubs include ground-hugging stems or low growth habit. Subshrubs may be largely herbaceous though still classified as woody, with overwintering perennial woody growth much lower-growing than deciduous summer growth. Some plants described as subshrubs are only weakly woody and some persist for only for a few years; others however, such as Oldenburgia paradoxa live indefinitely (though is still vulnerable to external effects), rooted in rocky cracks.

Small, low shrubs such as lavender, periwinkle, and thyme, and many shrub-like members of the family Ericaceae, such as cranberries and small species of Erica, are often classed as subshrubs.