The Tokyo Metro Yurakucho Line is a subway line in Japan owned and operated by Tokyo Metro. The line connects Wakōshi Station in Wakō, Saitama and Shin-Kiba Station in Kōtō, Tokyo. On maps, diagrams and signboards, the line is shown using the color "gold", and its stations are given numbers using the letter "Y".

The Tokyo Metro is a major rapid transit system in Tokyo, Japan, operated by the Tokyo Metro Co. With an average daily ridership of 6.84 million passengers, the Tokyo Metro is the larger of the two subway operators in the city; the other being the Toei Subway, with 2.85 million average daily rides.