Elections to North Down Borough Council were held on 17 May 1989 on the same day as the other Northern Irish local government elections.

The election used four district electoral areas to elect a total of 24 councillors.

Prior to the election three Ulster Unionist politicians, including George Green, had defected to the Conservative Party in Northern Ireland.

The election saw the Conservative presence in North Down doubling, with the Conservatives emerging as the single largest party on the council.

1985: 2 x DUP, 2 x UUP, 1 x Alliance, 1 x UPUP 1989: 2 x UPUP, 1 x DUP, 1 x Conservative, 1 x Alliance, 1 x UUP 1985-1989 Change: UPUP and Conservative gain from DUP and UUP 1985: 2 x UUP, 2 x Alliance, 1 x DUP, 1 x Independent Unionist 1989: 2 x Conservative, 1 x UUP, 1 x Alliance, 1 x DUP, 1 x Independent Unionist 1985-1989 Change: Conservatives (two seats) gain from UUP and Alliance 1985: 2 x UUP, 2 x Alliance, 2 x DUP, 1 x UPUP 1989: 2 x Conservative, 2 x UUP, 1 x Alliance, 1 x DUP, 1 x Independent 1985-1989 Change: Conservatives (two seats) and Independent gain from Alliance, DUP and UPUP 1985: 2 x UUP, 2 x Alliance, 1 x DUP 1989: 1 x Alliance, 1 x Conservative, 1 x UUP, 1 x DUP, 1 x Independent 1985-1989 Change: Conservative and Independent gain from UUP and Alliance