Southwest is the ordinal direction halfway between south and west, the opposite of northeast.

Southwest or south west may also refer to:

The Southwest United States

Southwest China

Southwest, Western Australia

Southwest Airlines, a domestic United States airline

The Southwest Biosphere Reserve in Australia; see List of Biosphere Reserves in Australia

Southwest Conference, the NCAA college football conference

Southwest England, principally the counties of Dorset, Somerset, Devon and Cornwall

Southwestern University School of Law, one of the oldest law schools in California

Southwestern University, a private university located in Georgetown, Texas

UT Southwestern Medical School, a prestigious medical school located in Dallas, Texas

Southwestern Art is a style of art prevalent in the desert Southwest of the United States, particularly centered in Santa Fe, New Mexico

Southwestern blot