It faces the Seto Inland Sea to the south, and the coastline is intricate and forms part of the Setonaikai National Park.

Onomichi has a mayor-council form of government with a directly elected mayor and a unicameral city council of 26 members.

In terms of national politics, Onomichi is part of the Hiroshima 5th district of the lower house of the Diet of Japan.

Shipyards have existed in Onomichi, Mukaishima, and Innoshima for a long time due to their location, which is blessed with water transport.

Additionally, six public high schools fall under the administration of the Hiroshima Prefectural Board of Education.

[9] The city is featured in the Japanese film Tokyo Story (1953) directed by Yasujirō Ozu, and became more famous during 80s and 90s decade thank to Nobuhiko Obayashi movies, as Exchange Students (1982), The Girl Who Leapt Through Time (1983), Lonely Heart (1985) or Goodbye for Tomorrow (also distributed under the titles Tomorrow or Ashita) [ja; cy] (1995), that were very popular between 80s teen generation.

The video game Yakuza 6: The Song of Life features a fictional district of Onomichi named Jingaicho based on the downtown area of the city as the main location in the story.