The Newcastle Local Municipality council consists of sixty-seven members elected by mixed-member proportional representation. Thirty-four councillors are elected by first-past-the-post voting in thirty-four wards, while the remaining thirty-three are chosen from party lists so that the total number of party representatives is proportional to the number of votes received. In the election of 1 November 2021 the African National Congress (ANC) lost its majority, winning a plurality of 22 seats. As of July 2024, the party has since lost five seats in by-elections, dropping to 17 seats, with the Inkatha Freedom Party (IFP) earning a plurality of 23 seats.
The following table shows the composition of the council after past elections.
The following table shows the results of the 2000 election.
The following table shows the results of the 2006 election.
The following table shows the results of the 2011 election.
The following table shows the results of the 2016 election.
In a by-election held on 5 April 2017, a ward previously held by the ANC was won by an independent candidate. Council composition was reconfigured as seen below:
The following table shows the results of the 2021 election.
The IFP took control of the municipality by entering into agreement with the DA, Team Sugar and other parties.
The following by-elections were held to fill vacant ward seats in the period since the election in November 2021.
After the three March by-elections, and the February by-election, the IFP had won four seats from the ANC, leaving them as the largest party, while in June 2024 the DA won a seat off the ANC. The following shows the composition of the council after the July 2024 by-election: