An Ceathrú Póilí (English: The Fourth Policeman;[1] founded 1983[2]) is an independent bookshop based in Cultúrlann McAdam Ó Fiaich on the Falls Road in the Gaeltacht Quarter of Belfast, Northern Ireland.

After the Ardscoil was destroyed by fire in a 1984,[4] the shop had a nomadic existence until the founding of Cultúrlann McAdam Ó Fiaich in 1991 in the old Broadway Presbyterian Church on Falls Road.

The centre was used as an Irish-medium secondary school (now Coláiste Feirste) and theatre space with the book shop located on the ground floor with An Caifé Glas (now known as Bia).

An Ceathrú Póilí was renovated in 2011 with Irish president Mary McAleese re-opening the cultural centre in 2011.

It hosts regular book launches in collaboration with publishers Coiscéim, Cló Iar-Chonnacht and An Gúm.