The post office is a prominent example of Mission Revival-influenced Art Deco design and is a significant building in the historic core of Santa Barbara.

It was designed by Pasadena architect Reginald Davis Johnson in the mid-1930s, and was completed in 1937.

[2] The Santa Barbara Post Office has a generally Spanish Colonial character that harmonizes with traditional local architecture, using a terra cotta roof and white stuccoed walls.

The bronze doors and building hardware are more characteristic of Art Deco than of Mission.

Streamline Moderne interior reliefs are by William Atkinson, using motifs typical of the 1930s.