Ballydown (from Irish Baile an Dúin, meaning 'townland of the hill-fort')[1] is a townland of 529 acres in County Down, Northern Ireland.

It is situated in the civil parish of Seapatrick and the historic barony of Iveagh Upper, Lower Half.

[2] The townland contains a rath (at grid ref: J1484 4672) which is a Scheduled Historic Monument and is also partly in the townland of Lisnaree.

[3]