Elections to Larne 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 15 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;">Alliance</span> !colspan=2 bgcolor="" | <span style="color:black;">Vanguard</span> !colspan=2 bgcolor="" | <span style="color:black;">DUP</span> !colspan=2 bgcolor="" | <span style="color:black;">UUP</span> !colspan=2 bgcolor="white"| <span style="black;">Others</span> |- |align="left"|Area A |N/A |1 |N/A |0 |N/A |1 |N/A |1 |N/A |1 |4 |- |align="left"|Area B |21.5 |1 |23.3 |1 |bgcolor="D46A4C"|36.9 |bgcolor="D46A4C"|1 |18.3 |1 |0.0 |0 |4 |- |align="left"|Area C |27.7 |2 |bgcolor="darkorange"|28.8 |bgcolor="darkorange"|2 |19.7 |1 |1.7 |0 |22.1 |2 |7 |- |- class="unsortable" class="sortbottom" style="background:#C9C9C9" |align="left"| Total |25.8 |4 |27.2 |3 |24.9 |3 |6.8 |2 |15.3 |3 |15 |-
1973: 1 x Alliance, 1 x UUP, 1 x Loyalist, 1 x Independent<br /> 1977: 1 x Alliance, 1 x UUP, 1 x DUP, 1 x SDLP<br /> 1973-1977 Change: SDLP gain from Independent, Loyalist joins DUP
1973: 3 x Loyalist, 1 x Independent Unionist<br /> 1977: 1 x DUP, 1 x Vanguard, 1 x Alliance, 1 x UUP<br /> 1973-1977 Change: Vanguard and Alliance gain from Loyalist (two seats), Loyalist joins DUP and Independent Unionist joins UUP
1973: 4 x Loyalist, 2 x Alliance, 1 x Independent<br /> 1977: 2 x Alliance, 2 x Vanguard, 2 x Independent, 1 x DUP<br /> 1973-1977 Change: Independent gain from Loyalist, Loyalist (three seats) join Vanguard (two seats) and DUP