Federal Health Minister Greg Hunt admits he should have said sorry sooner for using "strong language" in a meeting with the Katherine mayor.
Mr Hunt reportedly told Fay Miller from the Northern Territory she had to "f---ing get over" herself when they sat down last December in Parliament House.
"I should have apologised earlier. My fault," he told reporters in Canberra on Thursday.
The minister said he wanted to repeat his apology to Ms Miller publicly and sincerely.
"It was my fault and my responsibility and I accept that," he said.
In a letter to Malcolm Turnbull last month, Ms Miller said she wanted to bring to the prime minister's attention the unacceptable behaviour of Mr Hunt as a minister of the Crown in his government.
"Minister Hunt's behaviour towards me was totally unwarranted, disrespectful and unacceptable on every level," she said.
She had been leading a delegation to discuss a health package for her community following PFAS chemical contamination from nearby RAAF Base Tindal.
Coalition backbencher Luke Howarth welcomed his colleague's apology.
"No one's perfect. I've sort of let loose at times as well," Mr Howarth told reporters in Canberra.
But Labor frontbencher Brendan O'Connor offered a more scathing assessment of the delayed apology.
"He should focus on hospitals instead of bullying grandmothers," Mr O'Connor said.
"He needs to show much greater contrition, and frankly he should be focusing on the health needs of the nation."