Portmore Lough (from Irish Loch an Phoirt Mhóir 'lake of the great landing place') is a small lake in southwest County Antrim, Northern Ireland that drains water into nearby Lough Neagh.

It is roughly circular and covers an area of 286 hectares (710 acres).

[1] The lough is now part of a Royal Society for the Protection of Birds nature reserve.

[2] The lough is near the site of the former Portmore Castle, erected in 1664 and removed in 1761.

This article related to the geography of County Antrim, Northern Ireland is a stub.