Mid-century modern (MCM) is a movement in interior design, product design, graphic design, architecture and urban development that was popular in the United States and Europe from roughly 1945 to 1969, during the United States 's post– World War II period.

Mid-century modern is an interior design movement that rose to popularity in the United States in the middle of the twentieth century. Elements of mid-century modern interior design include clean lines, muted tones, a combination of natural and manmade materials, graphic shapes, vibrant colors, and integrating indoor and outdoor motifs.

Midcentury modern can be considered a subset of modern design, defined as the style that became popular in the early 1900s. However, when compared to the traditional definitions of modern design, midcentury modern design tends to be unashamedly retro and often makes use of bright accent color to emphasize this point.

Known for clean lines, minimal decoration, and a connection with nature, midcentury modern architecture is an American classic that began after World War II. A midcentury modern house plan is characterized by a very wide, low footprint with large, open spaces, floor-to-ceiling windows, and an emphasis on bringing the outdoors in.