Its neighbors on land are all special wards of Tokyo: Kōtō to the east, Minato to the north, Meguro to the west, and Ōta to the south.

In 1932, during the reorganisation of the municipal boundaries of Tokyo City following the 1923 Great Kantō earthquake, a smaller version of Shinagawa Ward was created.

The Ward's historic post-town function is retained today with several large hotels near the train station offering 6,000 rooms, the largest concentration in Tokyo.

Isuzu, a diesel engine and commercial truck manufacturer;[12] JTB Corporation, a major travel agency;[13] Nippon Light Metal, an aluminum and chemical products company;[14] MOS Burger (in the ThinkPark Tower, Ōsaki);[15] Lawson (East Tower of Gate City Ohsaki in Ōsaki),[16] Namco Bandai Holdings;[17] Namco Bandai Games;[18] Banpresto;[19] Rakuten,[20][21] Honda brand Acura;[22][citation needed] Toyo Seikan, a packaging manufacturer;[23] NSK Ltd., a bearing maker;[24] Fuji Electric, an electrical equipment manufacturer;[25] Imagica, a media post-production company;[26] Nippon Chemi-Con, an electronic components manufacturer;[27] Topy Industries, a machinery and automotive components company;[28] Gakken, a publishing and educational services company;[29] Comsys, a telecommunications construction and engineering company;[30] and Pola Cosmetics[31] all have their headquarters within Shinagawa Ward.

Marza Animation Planet also has its headquarters in Shinagawa on the 18th floor of the Tennoz Ocean Square near Tennōzu Isle Station.

[32][33] And since August 2018, Sega Sammy, best known for its Sonic the Hedgehog franchise and also the owner of the Nakano-based TMS Entertainment (which itself owns the aforementioned Marza Animation Planet), has its headquarters in Shinagawa at the Sumitomo Fudosan Osaki Garden Tower near Ōsaki Station.

[41] The Nikon HQ is supposed to be completed in 2024 and its address is: 5480-1, Nishioi 1-chome, Shinagawa-ku, Tokyo Other companies maintain branch offices or research facilities in Shinagawa Ward.

[43] Sony moved to Minato, Tokyo around the end of 2006 and closed the Osaki West Technology Center in Shinagawa around 2007.

Shinagawa is also home to the main motor vehicle registration facility for central Tokyo (located east of Samezu Station).

Shinagawa has sister-city relationships with Auckland in New Zealand, Geneva in Switzerland, and Portland, Maine, in the United States.