Coastal sage scrub, also known as coastal scrub, CSS, or soft chaparral, is a low scrubland plant community of the California coastal sage and chaparral subecoregion, found in coastal California and northwestern coastal Baja California. It is within the California chaparral and woodlands ecoregion, of the Mediterranean forests, woodlands, and scrub biome.

Coastal sage scrub is characterized by low-growing aromatic, and drought-deciduous shrubs adapted to the semi-arid Mediterranean climate of the coastal lowlands. The community is sometimes called "soft chaparral" due to the predominance of soft, drought-deciduous leaves in contrast to the hard, waxy-cuticled leaves on sclerophyllous plants of California's chaparral communities.

Characteristic shrubs and subshrubs include:

Larger shrubs include:

Herbaceous plants, grasses, and in some locales, cacti and succulents, are also part of the flora. Hesperoyucca whipplei, colloquially known as Chaparral Yucca, is commonplace throughout the climate zone.

The coastal sage scrub plant community is divided into three geographical subtypes—northern coastal scrub, southern coastal scrub, and maritime succulent scrub.

The coastal scrub communities are divided into three regions:

The Northern Coastal Scrub consists of prairie, which is terraces with deep alluvial soils, and scrub, which is found on steeper slopes and ravine areas. Evergreen shrubs and subshrubs, which are soft leaves. They are found in semi-open with a height of 2–3 meters, with multiple layers. Some examples of the plant species that can be found are Bush monkeyflower (Mimulus aurantiacus), Poison oak (Toxicodendron diversilobum), Coffee berry (Frangula californica), Golden yarrow (Eriophyllum confertiflorum).