The Tokyo Metro Chiyoda Line (東京メトロ千代田線, Tōkyō Metoro Chiyoda-sen) is a subway line owned and operated by Tokyo Metro in Tokyo, Japan. On average, the line carries 1,447,730 passengers daily (2017), the second highest of the Tokyo Metro network, behind the Tozai Line (1,642,378).
The line was named after the Chiyoda ward, under which it passes. On maps, diagrams and signboards, the line is shown using the color green, and its stations are given numbers using the letter "C".