The JR Yamanote line, Yamanote loop line, or sometimes simply called Tokyo Loop Line is a circular line in central Tokyo, and much used by commuters and visitors alike. The Yamanote line has a daily rider ship of up to 5 million people, stops at 30 stations and has a total length of 34.5 km (21.4 mi).

In Tokyo's complex rail network, the JR (Japan Railways) lines are distinct from the "Tokyo Metro" and "Toei Subway." The most famous and useful JR line for tourists is the Yamanote Line, the iconic green-coded loop that connects major hubs like Shinjuku, Shibuya, Tokyo Station, and Ueno. Other major JR lines include the Chuo Line (orange, crossing the city east-west), the Sobu Line (yellow), and the Keihin-Tohoku Line (blue, running north-south through Tokyo Station). JR lines are easily identifiable by the "JR" logo at station entrances and on the trains. Crucially, in 2026, these are the lines that are primarily covered by the Japan Rail Pass, whereas the subways require a separate ticket or an IC card like Suica or Pasmo. While JR lines often run above ground on elevated tracks, the subways are almost entirely underground. Knowing the difference is vital for cost-effective travel, as many stations (like Shinjuku) have both JR and subway sections that are disconnected behind separate fare gates.