Elections to Coleraine Borough Council were held on 18 May 1977 on the same day as the other Northern Irish local government elections. The election used three district electoral areas to elect a total of 20 councillors.
<small>Note: "Votes" are the first preference votes.</small>
|- class="unsortable" align="centre" !rowspan=2 align="left"|Ward ! % <br /> !Cllrs<br /> ! % <br /> !Cllrs<br /> ! %<br /> !Cllrs<br /> ! %<br /> !Cllrs<br /> ! % <br /> !Cllrs<br /> !rowspan=2|Total<br />Cllrs<br /> |- class="unsortable" align="center" !colspan=2 bgcolor="" | <span style="color:black;">UUP</span> !colspan=2 bgcolor="" | <span style="color:black;">DUP</span> !colspan=2 bgcolor="" | <span style="color:black;">Alliance</span> !colspan=2 bgcolor="" | <span style="color:black;">SDLP</span> !colspan=2 bgcolor="white"| <span style="black;">Others</span> |- |align="left"|Area A |bgcolor="40BFF5"|41.2 |bgcolor="40BFF5"|3 |18.5 |1 |4.7 |0 |21.9 |1 |13.7 |1 |6 |- |align="left"|Area B |bgcolor="40BFF5"|52.4 |bgcolor="40BFF5"|4 |0.0 |0 |16.9 |1 |11.2 |1 |19.5 |1 |7 |- |align="left"|Area C |24.6 |3 |bgcolor="#D46A4C"|30.4 |bgcolor="#D46A4C"|1 |11.1 |1 |0.0 |0 |33.9 |2 |7 |- |- class="unsortable" class="sortbottom" style="background:#C9C9C9" |align="left"| Total |38.2 |10 |17.6 |2 |10.6 |2 |10.5 |2 |23.1 |4 |20 |-
1973: 4 x UUP, 1 x SDLP, 1 x Independent Unionist<br /> 1977: 3 x UUP, 1 x SDLP, 1 x DUP, 1 x Independent Unionist<br /> 1973-1977 Change: DUP gain from UUP
1973: 5 x UUP, 2 x Alliance<br /> 1977: 4 x UUP, 1 x Alliance, 1 x SDLP, 1 x Independent Unionist<br /> 1973-1977 Change: SDLP gain from Alliance, Independent Unionist leaves UUP
1973: 4 x UUP, 2 x Independent, 1 x Alliance<br /> 1977: 3 x UUP, 2 x Independent, 1 x DUP, 1 x Alliance<br /> 1973-1977 Change: DUP gain from UUP