The Seto-Chūō Expressway (瀬戸中央自動車道, Seto-Chūō Jidōsha-dō) is a tolled expressway that connects Okayama and Kagawa prefectures in Japan across a series of five small islands in the Seto Inland Sea.

Built between 1978 and 1988, it is one of the three routes of the Honshu-Shikoku Bridge Expressway Company connecting Honshū and Shikoku islands.

The route is signed E30 under Ministry of Land, Infrastructure, Transport and Tourism's "2016 Proposal for Realization of Expressway Numbering.

The expressway has four lanes along the entire route from Sakaide, Kagawa to Kurashiki in Okayama.

The southern remainder of the route has a speed limit set at 80 km/h.