List of tallest structures envisioned for Tokyo
Tokyo is the most populated of Japan's 47 prefectures. With around 14 million inhabitants in the prefecture and 40 million in the Metropolitan area as of 2024, Tokyo ranks among the largest metropolises in the world. Despite Japan being the country with the highest average age globally in 2024, according to The World Factbook, and experiencing negative population growth, the country underwent a period of rapid population growth after World War II, particularly in the capital, Tokyo. This growth gave rise to several megaprojects aimed at addressing ecological issues and space shortages caused by overpopulation. This article lists visionary megaprojects announced during the 1980s and 1990s, coinciding with Japan's asset price bubble period, as well as more recent projects with heights of 300 meters or more.
Tallest visionary structures
This table lists visionary construction projects, also referred to as 'visions' by the Council on Tall Buildings and Urban Habitat (CTBUH), with heights of at least.| Name | Height m | Floors | Start | Finish | Location | Notes |
| Tokyo Tower of Babel | 10 km | 1969 | — | — | — |
|
| X-Seed 4000 | 4000 | 800 | — | — | — | |
| TRY-2004 | 2004 | 400 | — | — | — | |
| Aeropolis 2001 | 2001 | 500 | — | — | — | |
| Sky Mile Tower | 1700 | — | — | 2045 | — | |
| M.O.T.H.E.R. | 1321 | 220 | — | — | — | |
| The Spiral | 1000 | 200 | — | — | — | |
| Sky City 1000 | 1000 | 196 | — | — | — | |
| Hyper Building | 1000 | — | — | — | — | |
| Millenium Tower | 840 | 180 | — | 2009 | — | |
| DIB-200 | 800 | 200 | — | — | — | |
| Holonic Tower | 600 | 120 | — | — | — | |
| Shimizu Super High Rise | 550 | — | — | — | — | |
| W350 | 350 | 70 | — | 2041 | Chiyoda |