Portmuck (from Irish Port Muc, meaning 'port/harbour of pigs')[1] is a townland of 235 acres in County Antrim, Northern Ireland.

It is situated in the civil parish of Islandmagee and the historic barony of Belfast Lower.

[2] The townland has given its name to a little island just off the coast called Isle of Muck,[1] which is a nature reserve.