The Northern Line is a railway line in Thailand, running between the capital Bangkok and the northern city of Chiang Mai. It is the second longest railway line in Thailand at 751 kilometres (467 mi) long, has 130 operational stations and halts, and is operated by the State Railway of Thailand. The line first opened in 1896. Major cities served by the line include Bangkok, Ayutthaya, Nakhon Sawan, Phitsanulok, Lampang, and Chiang Mai.

Krung Thep Aphiwat Central Terminal, also known by its former name Bang Sue Grand Station, is the central passenger terminal in Bangkok and the current railway hub of Thailand. It replaced the existing Hua Lamphong railway station as the city's central railway station, with long-distance rail services operating from here from 19 January 2023. The station was opened on 2 August 2021 as part of the operation of the SRT Red Lines, and from May 2021 to September 2022 served as a COVID-19 vaccination center. It is linked to the Bang Sue MRT station via an underground walkway.