The Madrid Metro (Spanish: Metro de Madrid) is a rapid transit system serving the Spanish capital city of Madrid and its surrounding metro area. First opened in 1919, the system has regularly undergone numerous extensions over the next century, bringing it to today's network which comprises thirteen "conventional" (heavy-rail) lines and three light-rail lines known as Metro Ligero. The network is largely owned and operated by Metro de Madrid S.A., a public company owned by the Government of the Community of Madrid.
As of September 2025, the conventional lines have a combined length of 296.6 kilometres (184.3 mi), making Madrid's Metro system the 20th longest rapid transit system in the world, the 6th longest in the world outside of China, and the 3rd longest in Europe behind only the Moscow Metro and the London Underground; the three light-rail lines add a further 27.8 kilometres (17.3 mi) to the total length of the network. The whole system transported a total of 715 million passengers in 2024 – in this metric Madrid's system stands as the 29th most-used in the world and the 5th most-used in Europe, behind Moscow, Paris, London and Istanbul.