CF Os Belenenses

Clube de Futebol Os Belenenses is a Portuguese sports club located in the freguesia of Belém, Lisbon. It was officially founded on 23 September 1919 as a football club. It also has about ten sections, among which basketball, rugby, athletics and handball stand out. Since the 2024–25 season it has played in the Terceira Liga, the third tier of football in Portugal.

The club won several titles in the early days of Portuguese football, including three Campeonatos de Portugal, three Taças de Portugal and the First Division title in 1945–46. For almost six decades, Os Belenenses was the only club to break the dominance of the "big three" — Benfica, Sporting and Porto — in the Portuguese league honours list, until Boavista F.C. managed to win in 2000–01.

In the 2018–19 season the professional sports limited company "B-SAD" retained Belenenses' place in the Portuguese First Division and, for legal purposes, broke all ties with the historic entity. The remaining sections, including a senior team, have kept both the history and the assets and the original name. B-SAD disappeared in the 2023–24 season.

Os Belenenses is considered the third team in the Portuguese capital in number of supporters. It has a total of 59 branches and 8 registered supporters' groups, inside and outside the country.