Line 3
- 3 (Los Angeles Railway)
- 3 (New York City Subway service)
- 3 Line (Sound Transit)
- 3 Train (disambiguation)
- Ampang Line
- Busan Metro Line 3
- Enbridge Line 3
- L3 Kingsford Line
- Line 3 (Athens Metro)
- Line 3 (Beijing Subway)
- Line 3 (Budapest Metro)
- Line 3 (Changchun Rail Transit)
- Line 3 (Changsha Metro)
- Line 3 (Chengdu Metro)
- Line 3 (Chennai Metro)
- Line 3 (Chongqing Rail Transit)
- Line 3 (Dalian Metro)
- Line 3 (Dongguan Rail Transit)
- Line 3 (Foshan Metro)
- Line 3 (Guangzhou Metro)
- Line 3 (Hangzhou Metro)
- Line 3 (Hanoi Metro)
- Line 3 (Harbin Metro)
- Line 3 (Hefei Metro)
- Line 3 (Jinan Metro)
- Line 3 (Kunming Metro)
- Line 3 (Madrid Metro)
- Line 3 (Metrovalencia)
- Line 3 (Metrovía)
- Line 3 (Moscow Metro)
- Line 3 (Mumbai Metro)
- Line 3 (Nanchang Metro)
- Line 3 (Nanjing Metro)
- Line 3 (Nanning Metro)
- Line 3 (Ningbo Rail Transit)
- Line 3 (Pune Metro)
- Line 3 (Qingdao Metro)
- Line 3 (Rio de Janeiro)
- Line 3 (Saint Petersburg Metro)
- Line 3 (Shanghai Metro)
- Line 3 (Shenzhen Metro)
- Line 3 (Shijiazhuang Metro)
- Line 3 (Suzhou Metro)
- Line 3 (São Paulo Metro)
- Line 3 (Tianjin Metro)
- Line 3 (Wuhan Metro)
- Line 3 (Wuxi Metro)
- Line 3 (Xi'an Metro)
- Line 3 (Xiamen Metro)
- Line 3 (Xuzhou Metro)
- Line 3 (Zhengzhou Metro)
- Line 3 Ontario
- Line 3 Red (Montreal Metro)
- Line 3 Scarborough
- Line 3 of the Guadalajara urban rail system
- MRT Line 3 (Metro Manila)
- Mexico City Metro Line 3
- Mexico City Metrobús Line 3
- Mosin–Nagant
- Paris Métro Line 3
- Purple Line (Kolkata Metro)
- Route 3 (MTA Maryland)
- Santiago Metro Line 3
- Seoul Subway Line 3
- Taipei Metro Line 3
- U3 (Vienna U-Bahn)
- Whip (politics)
- Île-de-France tramway Line 3