Line 21 may refer to:
Closed Captioning
- EIA-608, a standard for closed captioning for NTSC TV broadcast, also known as "line 21 captions"
Telecommunications
Line 21, a Hungarian telecommunications company Vodafone Hungary
A Railway Line
In operation
- Line 21 (Guangzhou Metro), a metro line of the Guangzhou Metro in China
- Line 21 (Zürich), Switzerland
- Yangluo Line, a metro line of the Wuhan Metro in China
Under Planning
- Line 21 (São Paulo Metro), a future metro line of the São Paulo metro
- Line 21 (Shanghai Metro), a future metro line of Shanghai Metro
This disambiguation page lists articles associated with the title Line 21.If an internal link led you here, you may wish to change the link to point directly to the intended article. Category: