Aincille (French pronunciation: [ɛ̃sil];[3] Basque: Aintzilla)[4] is a commune in the Pyrénées-Atlantiques department in the Nouvelle-Aquitaine region in southwestern France.

The town is part of Cize Country in the former Basque province of Lower Navarre.

The Urtchipea rises in the south of the commune and flows northwest gathering many tributaries and joins the Nive de Beherobie at Saint-Michel.

The Sassitako erreka rises southwest of the village and flows northwest joining the Laurhibar east of Saint-Jean-Pied-de-Port.

[11] Quarterly, first Azure a bridge of Or masoned in sable debruised over a wave of argent in base, in chief 3 stars the same arranged in fesse; second of Or with an eagle displayed in sable; three vert a cow of Or collared and belled in azure posed in base surmounted by a sheep of argent horned in Or; fourth azure with a church in Or in profile roofed the same extended at dexter with a porch abased and surmounted at dexter by a belltower and steeple the same supporting a cross in sable, windows and doors the same..