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 is 37.3 kilometres (23.2 mi) long with 20.8 kilometres (12.9 mi) of that stretch consisting of bridges, chiefly the Great Seto Bridge. The expressway has four lanes along the entire route from Sakaide, Kagawa to Kurashiki in Okayama. The speed limit is 100 km/h from the expressway's northern terminus at Hayashima Interchange in Kurashiki to Kojima Interchange, also in Kurashiki. The southern remainder of the route has a speed limit set at 80 km/h.

TB= Toll booth, SA= Service Area, PA= Parking Area

Prefecture	Location	km	mi	Exit	Name	Destinations	Notes
Through to AH1 San'yō Expressway
Okayama	Kurashiki	0	0.0	1/TB	Hayashima	AH1 San'yō Expressway, National Route 2– Hiroshima, Okayama, Kobe, Okayama Airport
		6.8	4.2	PA	Tsubue
		8.2	5.1	2	Mizushima	Okayama Prefecture Route 21
		15.0– 15.6	9.3– 9.7	SA	Kōnoike		The northbound SA is at 15.0 km, the southbound SA is at 15.6 km
		18.8	11.7	3	Kojima	Okayama Prefecture Route 21– Mizushima Industrial Area, Okayama
Kagawa	Sakaide	22.6	14.0	—	Hitsuishijima	Kagawa Prefecture Route 273– Hitsuishi Island	General vehicles are prohibited from using the exit
		24.4	15.2	—	Iwakurojima	Unnamed Road– Iguro Island	General vehicles are prohibited from using the exit
		26.4	16.4	—	Yoshima	Kagawa Prefecture Route 274– Yoshima Island	General vehicles are prohibited from using the exit
		26.4	16.4	PA	Yoshima
		34.7	21.6	4	Sakaide-kita	Kagawa Prefecture Route 192– Central Sakaide
		37.3	23.2	5/TB	Sakaide	Takamatsu Expressway, National Route 11– Central Sakaide, Takamatsu, Matsuyama
Through to Takamatsu Expressway
1.000 mi = 1.609 km; 1.000 km = 0.621 mi       Incomplete access

• Japan National Route 30

• Honshu-Shikoku Bridge Expressway Company Limited: E30 SETO CHUO EXPWY