The apology related to Clark’s March appearance on television show New Zealand Today, which resulted in a breach of the council’s code of conduct.
He also used a homophobic slur.
Following an extraordinary council meeting on July 26, Clark was requested by fellow councillors to make a "sincere" public apology for his actions at a full council meeting.
That opportunity came on Tuesday, as councillors met to discuss a representation review.
"I need to make a public apology, which is a part of the commitment I gave at the end of the code of conduct inquiry into the New Zealand Today TV show that I was party to," Clark said early in the meeting.
"So I just wish to acknowledge to my elected colleagues and to the community that by participating the way I did in that interview, that I breached the code of conduct expectations of an elected member and portrayed the city in a very poor light."
Clark also expressed his thanks to deputy mayor Tom Campbell, saying it had not been easy to "mop up some of the mess that we’ve had with that".
The mayor has not explicitly apologised for his use of language on the television show.
In April, he apologised in a Stuff article to "anyone who felt offended" by the interview, before providing a written apology for a July meeting.
The written apology was read out in the mayor’s absence, acknowledging he had discredited the city in an interview that was "not good". He was then requested to make a "sincere" in-person apology.
His public apology on Tuesday was his second in as many weeks.
On July 30, he apologised at a council meeting for breaching the council's code of conduct at a United Fire Brigades’ Association event in March.
A series of allegations were levelled at Clark in relation to his behaviour at the meeting, including derogatory comments to the female MC about her appearance and competence, and calling volunteer firefighters second-class citizens.
An investigation report into the mayor’s actions said Clark left the woman so upset, she wished the ground would "open up and swallow her".
Clark is in his first term as mayor but has ruled out standing again at the next election.
He spent one term as a councillor before securing the top job at the 2022 election, almost 3000 votes clear of his nearest rival.
- LDR is local body journalism co-funded by RNZ and NZ On Air